heliophysics - User contributions [en]

07/23/2012 23:00:00 UTC

2017-03-16T20:52:35Z

Davidwebb:

This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

[Added by D. Webb]

- M. Temmer: A key element for the extreme character of the July 23, 2012 eruption is a high level of flare energy release over a long time range (max acceleration 2.2km/s^2, ~30 minutes of acceleration phase). Due to an efficient magnetic reconnection process the CME might reach a very high speed (max v=2580+/-280km/s derived from GCS 3D model) that is sustained by the prolonged energy release. The underlying mechanism which is able to build up the energy in the source region as well its conversion into such high kinetic energy is beyond the limit of information from observational data. We encourage modelers to provide further insight into the physics of source regions and reconnection processes related to such extreme events. The very high mass of the CME (1.5x10^16 g) as well as the reduced solar wind density in IP space (1-2/cm^3) due to A) the prior CME from July 19, 2012, B) general low density owing to the low solar activity, may have been the decisive factors for making this event super-fast. In addition, the largely radial orientation of the interplanetary magnetic field, due to its stretching by the CME from July 19, may have reduced the pile-up of solar wind and delayed its replenishment. [Temmer and Nitta, Solar Physics, under review]

REFERENCES:

*Russell, C. et al., ApJ, 770, 38, 2013
*Ngwira, C. et al., GRL, 2013
*Baker, D., Space Weather, 11, 585, 2013
*Liu, D.L. et al., Nature Comm., 5, 4381, 2014.
*Gopalswamy et al., E,P&S, 66, 104, 2014
*Temmer, M. and N. Nitta, Interplanetary Propagation behavior of the fast coronal mass ejection on 23 July 2012, Solar Phys., 290, 919, 2015. Doi: 10.1007/s11207-014-0642-3.
*Liou, K, C.-C. Wu, M. Dryer, S.-T. Wu, N. Rich, S. Plunkett, L. Simpson, C. D. Fry, and K. Schenk, Global Hybrid Simulation of Extremely Fast Coronal Mass Ejection on 23 July 2012, JASTP, 121, 32-41, 2014.
*Riley, P., R. M. Caplan, J. Giacalone, D. Lario, and Y. Liu, 2016, Properties of the Fast Forward Shock Driven by the 2012 July 23 Extreme Coronal Mass Ejection, Astrophys. J., 819, 57, doi: 10.3847/0004-637X/819/1/57.
*Zhu, B.; Liu, Y. D.; Luhmann, J. G.; et al., Solar Energetic Particle Event Associated with the 2012 July 23 Extreme Solar Storm, 2016, Astrophys. J., 827, 146 (study of the SEP event).
*Gopalswamy, N., S. Yashiro, N. Thakur, P. Mäkelä, H. Xie and S. Akiyama, 2016, The 2012 July 23 Backside Eruption: An Extreme Energetic Particle Event?, Astrophysical Journal, 833, 216, doi: 10.3847/1538-4357/833/2/216.
*Liu, Ying D.; Hu, Huidong; Zhu, Bei; Luhmann, Janet G.; Vourlidas, Angelos; Structure, Propagation, and Expansion of a CME-Driven Shock in the Heliosphere: A Revisit of the 2012 July 23 Extreme Storm, 2017, Astrophys. J., 834, 158 (study of the structure, propagation and expansion of the shock).

03/08/2012 11:00:00 UTC

2017-03-10T21:24:59Z

Davidwebb: /* References */

=Comment Section=
*A fair ICME event, but strong solar source
**X1 flare, fast CME, originated from the eastern hemisphere (~N18E42)
**Solar wind plasma data is corrupted.

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2012030800.png|350px]]
[[File:plot_sw_mag_2012030800.png|400px]]
[[File:plot_sw_vel_2012030800.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

==GOES X-RAY FLUX==
[[File:20120305_goes.png|500px]] 
The GOES X-ray Flux of the flare associated with the event. The vertical line approximately denotes the flare peak time. 

=Video Data=

=References=

*Wang, R., Liu, Y. D., Yang, Z., and Hu, H., Magnetic Field Restructuring Associated with Two Successive Solar Eruptions, 2014, Astrophys. J., 791, 84 (http://iopscience.iop.org/article/10.1088/0004-637X/791/2/84/pdf)
*Liu, Y. D., Luhmann, J. G., Lugaz, N., Möstl, C., Davies, J. A., Bale, S. D., and Lin, R. P., On Sun-to-Earth Propagation of Coronal Mass Ejections, 2013, Astrophys. J., 769, 45 (http://iopscience.iop.org/article/10.1088/0004-637X/769/1/45/pdf)
*Liu, Y. D., Richardson, J. D., Wang, C., and Luhmann, J. G., Propagation of the 2012 March Coronal Mass Ejections from the Sun to Heliopause, 2014, Astrophys. J. Lett., 788, L28 (http://iopscience.iop.org/article/10.1088/2041-8205/788/2/L28/pdf)
*Chintzoglou, G., Patsourakos, S., and Vourlidas, A., 2015, Formation of Magnetic Flux Ropes During Confined Flaring Well Before the Onset of a Pair of Major Coronal Mass Ejections, Astrophys. J., 809, 34, doi:10.1088/0004-637X/809/1/34.
*Wood, B. E., J. L. Lean, S. E. McDonald, and Y.-M. Wang (2016), Comparative ionospheric impacts and solar origins of nine strong geomagnetic storms in 2010–2015, J. Geophys. Res., 121, 4938–4965, doi:10.1002/2015JA021953.
*Patsourakos, S. et al., The Major Geoeffective Solar Eruptions of 2012 March 7: Comprehensive Sun-To-Earth Analysis, Astrophys. J., 817, 14, 2016.
*Syntelis, P,, Gontikakis, C, Patsourakos, S, and Tsinganos, K., 2016, The spectroscopic imprint of the pre-eruptive configuration resulting into two major coronal mass ejections, A&A, 588, A16.

07/23/2012 23:00:00 UTC

2017-03-08T16:18:56Z

Davidwebb:

This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

[Added by D. Webb]

- M. Temmer: A key element for the extreme character of the July 23, 2012 eruption is a high level of flare energy release over a long time range (max acceleration 2.2km/s^2, ~30 minutes of acceleration phase). Due to an efficient magnetic reconnection process the CME might reach a very high speed (max v=2580+/-280km/s derived from GCS 3D model) that is sustained by the prolonged energy release. The underlying mechanism which is able to build up the energy in the source region as well its conversion into such high kinetic energy is beyond the limit of information from observational data. We encourage modelers to provide further insight into the physics of source regions and reconnection processes related to such extreme events. The very high mass of the CME (1.5x10^16 g) as well as the reduced solar wind density in IP space (1-2/cm^3) due to A) the prior CME from July 19, 2012, B) general low density owing to the low solar activity, may have been the decisive factors for making this event super-fast. In addition, the largely radial orientation of the interplanetary magnetic field, due to its stretching by the CME from July 19, may have reduced the pile-up of solar wind and delayed its replenishment. [Temmer and Nitta, Solar Physics, under review]

REFERENCES:

*Russell, C. et al., ApJ, 770, 38, 2013
*Ngwira, C. et al., GRL, 2013
*Baker, D., Space Weather, 11, 585, 2013
*Liu, D.L. et al., Nature Comm., 5, 4381, 2014.
*Gopalswamy et al., E,P&S, 66, 104, 2014
*Temmer and Nitta, Solar Phys., 290, 919, 2015
*Liou, K, C.-C. Wu, M. Dryer, S.-T. Wu, N. Rich, S. Plunkett, L. Simpson, C. D. Fry, and K. Schenk, Global Hybrid Simulation of Extremely Fast Coronal Mass Ejection on 23 July 2012, JASTP, 121, 32-41, 2014.
*Zhu, B.; Liu, Y. D.; Luhmann, J. G.; et al., Solar Energetic Particle Event Associated with the 2012 July 23 Extreme Solar Storm, 2016, Astrophys. J., 827, 146 (study of the SEP event).
*Liu, Ying D.; Hu, Huidong; Zhu, Bei; Luhmann, Janet G.; Vourlidas, Angelos; Structure, Propagation, and Expansion of a CME-Driven Shock in the Heliosphere: A Revisit of the 2012 July 23 Extreme Storm, 2017, Astrophys. J., 834, 158 (study of the structure, propagation and expansion of the shock).

03/17/2015 04:00:00 UTC

2017-03-08T16:15:35Z

Davidwebb: /* References */

=Comment Section=
*varSITI campaign event
*Largest geomagnetic storm at Earth for solar cycle 24, this event registered a Dst peak of -228 nT.
*Based on both the in-situ signature of the event and the ENLIL solar wind prediction for this date, I think it is likely a CIR played a role in making it so strong. There is a strong coronal hole at the South Pole and the ENLIL simulation ([[http://helioweather.net/archive/2015/03/cmes201503_vel3r2e1b.mp4]]) shows a fairly fast stream that interacts with the CME, and this fast speed stream (~600 km/s) shows up in ACE data as well. Based on the C2 and C3 images for the day, it appears there is a slow CME launching around noon on the 14th with a small but visible filament. On the morning of the 15th a partial halo CME, associated with a long duration flare that fell just short of M class (C9.1) and from the same active region (AR 12297), launched propagating to the East of the Sun Earth line. I think it is likely that an interaction between the CME+shock of this event and the previous blob CME, as well as the added energy from the CIR and fast speed stream behind the CME caused the severity of the geomagnetic activity at the Earth (Hess)
*This super storm is produced through a combination of effects: (1) strong magnetic field in the sheath region (> 25 nT at peak)) and ejecta (>30 nT at peak, (2) Bs field encompasses the entire duration of the ejecta, due to that the axis of the flux rope is highly inclined toward the north-south direction, (3) the interaction with CIR, and almost contained in a CIR region. Such containment by CIR prevents the expansion of the flux rope, thus makes the flux rope small in size by strong in magnetic field (Jie Zhang).
*This may be a kind of CME-CME interaction event. We have a large filament, embedded in a magnetic flux rope, close to the AR which released this highly geoeffective CME. Part of the filament (or flux rope) erupted - or at least, left the low corona - already on March 14 (around 12UT). The final and major eruption on March 15 seems to interact with the first disturbance. The interacting sectors might propagate close to Earth direction. This might be a reason for the complex in-situ signatures (two flux ropes?) as well as the increased geoeffectiveness (Manuela Temmer).
*I was looking at the structure of the ejecta using the Grad-Shafranov reconstruction method. What amazes me is that the cloud can be reconstructed fairly well by the technique despite the magnetic field fluctuations. The reconstruction shows two flux ropes, which is consistent with two interacting CMEs seen in the coronagraph images. (Ling Liu)
*With the ElEvo model results for the March 15 04:00 UT CME shock propagation from Sun to Earth, I need a quite low value of gamma to get the Wind speed and arrival time right, which reflects that this CME did not seem to experience much drag during interplanetary propagation. If the CME apex is really about 40° away from the Earth (as indicated by the source region position), I think its very surprising that Earth is hit by the flux rope. I think this is only possible if the flux rope had a very low inclination to the ecliptic, or as said before that there was some interaction with the CME on March 14. Maybe the drag parameter is low because the CIR was pushing from behind, adding an additional force? (Christian Moestl)
*For Christian's high inclination problem, I think that an explanation is the deflection. My theory proposed that fast CMEs deflect toward east and slow CMEs deflect toward west (Wang et al., JGR, 119, 5117, 2014). Also there are in situ signatures of such possible deflection. From fitting results of my velocity-modified flux rope model, we find there is significant propagation velocity of the CME at 1 AU which is perpendicular to the Sun-Earth line (in +y direction in GSE coordinates). (Yuming Wang)

=USTC mini workshop discussion[2015/06/12]=

==Initiation near the Sun==

Flare: raise/decay time 58 min / 6 hours

CME: Initial speed ~500 - 1000 km/s

Complex eruption. At least three different filaments involved.

Two smaller ones on the left erupted. The longer one on the right was active but not erupted.

First jet like filament eruption at the time of ~00:38UT produced a short duration C2 flare. Second filament eruption at the time of ~01:15UT (flare onset) produced the long duration C9 flare and the CME.

The source region of the flare/filament was not located near the main neutral line of the strong main bipolar region. It was located on the south west of the main active region.

Strong magnetic field cancellation observed near the source region of the second filament eruption.

There was an extended coronal hole in the south west of the active region which might be the source of the fast stream following the ICME.

==Propagation in the interplanetary space==

There was consensus that CME1 on the March 14 and CME2 on the March 15 were not interacted. There was no evidence of interaction in LASCO C2 and C3 images.

Manuela Temmer: just a comment - from the below given results for the CME speed over the distance range 4-20Rs, we derive a deceleration of -20 to -27 m/s^2. This is a rather high value compared to the average as derived from LASCO CDAW results.
[[File:cme_acceleration_CDAW.png]]

From Phil Hess’s measurements based on the spherical bubble model, the CME speed at 4 Rs near 02:00UT is 1100 km/s. It decelerated to 750 km/s at the 20 Rs at 05:30 UT. The propagation direction of this CME is S11W39.

From the GCS model fitting results done by USTC STEP group, the propagation direction is S11W46.

The speed at 02:00UT was 1000 km/s. When it propagated at 20 Rs near the time of 06:06UT, its speed is 720km/s.

From the USTC’s Ice Cream Cone model’s fitting results, this CME propagated with the speed of 807 km/s in the LASCO field of view. The propagation direction is S10W35. The angular width is 115 degree.

Observed transit time: 51 hours (flare onset to shock arrival) || 57 hours (flare onset to ICME arrival)

Model calculations:

Assume: CME initial speed = 800km/s

Background solar wind speed=500 km/s

Results SPM2 [Zhao et al. JGR, 2014, http://www.spaceweather.ac.cn/groupmodel.php?group=sigma ] 53 hours for shock

DMB [Bojan Vrsnak, http://oh.geof.unizg.hr/DBM/dbm.php]: 57 hours for ICME

Assume: CME initial speed = 800km/s

Background solar wind speed=400 km/s

Results: SPM2[Zhao et al. JGR, 2014, ] 60 hours for shock

DMB[Bojan Vrsnak]: 63 hours for ICME

==In situ properties and geoeffectiveness==

Questions:

What is the connection between the solar and interplanetary observations?

Why this high inclined and not earth directed CME arrived at the Earth?

Why is this a super geomagnetic storm considering the small flare of C9 class and intermediate CME speed of less than 1000 km/s?

Why is the magnetic field irregular? i. e. not a typical magnetic cloud?

==Geospace response==

=Image Data=

==In-situ data==
[[File:20150315_magplasma.png]]
[[File:20150315_mag.png]] 
*These are in-situ plots based on the ACE daily text files, I will update them when the cdf data becomes available. In these plots the shock is very clear, but beyond that any ejecta signature is weak and there does not appear to be any strong Magnetic cloud. But there are two clear and distinct periods of strong -Bz. (Hess)

[[File:WindData.png|600px]]
*Manuela Temmer: Wind in-situ data, and attempt to fit the flux rope (Lundquist model).

==LASCO/Kanzelhöhe==
Image collection of white light and chromospheric data, showing two disturbances and the partly erupted filament which is related to the CME producing AR:
[link http://www.uni-graz.at/~temmerma/download/varsiti/20150315.pdf]

==GOES Plot==
[[File:20150315_goes.png]]

==SOHO/LASO measurement==
[[File:Hess_heights.png|700px]]
*Height-Time plot based on SOHO/LASCO measurement
[[File:Hess_velocity.png|700px]]
*Velocity-Time plot from SOHO/LASCO H-T measurement
*Height-Time measurement data from SOHO/LASCO: [[Hess_measurement.docx]]

measurements from CORIMP (max speed given as 918 km/s, central PA as 262)
http://alshamess.ifa.hawaii.edu/CORIMP/realtime/soho/lasco/detections/2015/03/15/cme_kins/plot_kins_quartiles_savgol_20150315_000006.jpg

== Interplanetary Propagation ==
Christian Möstl and Tanja Rollett:
ElEvo results (parameters already tweaked so it matches Wind arrivals):
shock arrival at Wind: March 17 03:50 UT
arrival speed 665 km/s

Wind observations (taken from the Wu et al. draft):
shock arrival March 17 03:59 UT
arrival speed of the sheath is 500- 600 km/s, about 100 km/s less than the ElEvo arrival speed.

This model/plot can be adjusted very easily if you think the CME initial speed, direction and launch time should be different.

initial CME parameters:
inital speed at 15 Rs: 1120 km/s, at time 2015 March 15 04:00 UT, direction to Earth west 39°
the speed was taken from Kevin Schenk real time email, consistent with Gopalswamy et al. proceeding; same for direction. Thus I assume that the source region position is similar to the CME direction. Because the flare happens inside the AR and there are no large coronal holes nearby, it should be relatively safe to assume this direction as the CME propagation direction. The asymmetric halo with more material to the west of the Sun also supports this. Other Parameters: background wind: 400 km/s, gamma: 0.1, ellipse aspect ratio 1.6, full width: 100° in heliospheric longitude.

We have also experimented with the initial conditions given by the above LASCO measurements for the CME shock, using launch on March 15 08:06 UT, at 28.7 Rs, speed of 700 km/s
but the arrival times we get are about 0.5-1 day to late compared to the observed one at Wind, even with very extreme choices for gamma and the ellipse aspect ratio or a direct propagation towards Earth the observed arrival time is not reproduced. Thus, it seems that the (projected) initial speed is too slow for this event - ElEvo with 1120 km/s initial speed as indicated by the real time measurements is able to reproduce the observed arrival time and speed as shown above.

[[File:elevo_15_mar_2015_storm_small2.png]]

=Video Data=
[http://solar.gmu.edu/wiki/upload/phess4/201503171.gif AIA 171 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503193.gif AIA 193 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503304.gif AIA 304 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/2015031600.gif AIA 1600 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503hmi.gif HMI movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503c2.gif C2 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503c3.gif C3 movie] 
movie from CORIMP catalogue:
http://alshamess.ifa.hawaii.edu/CORIMP/realtime/soho/lasco/detections/2015/03/15/cme_ims_orig_20150315_000006/movie_C3.html

=References=
- ElEvo model: Möstl et al. 2015 Nature Communications, open access: http://www.nature.com/ncomms/2015/150526/ncomms8135/full/ncomms8135.html

- P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf

- Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015.

- Kamide, Y. & K. Kusano, Space Weather, 13, 2015.

- Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.

- Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

- Wang, Y. et al., On the Propagation of a Geoeffective Coronal Mass Ejection during March 15 – 17, 2015, JGR, 121, 7423 (2016).

- Jakosky, B. M., J. M. Grebowsky, J. G. Luhmann, D. A. Brain, Initial results from the MAVEN mission to Mars. Geophys. Res. Lett. 10.1002/2015GL065271 (2015).

- Cherniak, I., I. Zakharenkova, and R. J. Redmon (2015), Dynamics of the high-latitude ionospheric irregularities during the 17 March 2015 St. Patrick’s Day storm: Ground-based GPS measurements, Space Weather, 13, 585–597,doi:10.1002/2015SW001237.

- Le, G., et al. (2016), Magnetopause erosion during the 17 March 2015 magnetic storm: Combined field-aligned currents, auroral oval, and magnetopause observations, GRL, 43, 2396–2404, doi:10.1002/2016GL068257.

- Wood, B. E., J. L. Lean, S. E. McDonald, and Y.-M. Wang (2016), Comparative ionospheric impacts and solar origins of nine strong geomagnetic storms in 2010–2015, J. Geophys. Res., 121, 4938–4965, doi:10.1002/2015JA021953.

- Wu, C.-C., et al., The first super geomagnetic storm of solar cycle 24: “The St. Patrick’s day event (17 March 2015)”, Earth, Planets and Space (2016) 68:151 DOI 10.1186/s40623-016-0525-y.

- Wang, R., Liu, Y. D., et al., Sympathetic solar filament eruptions, 2016, Astrophys. J. Lett., 827, L12.

- Marubashi, K., Cho, K.-S., Kim, R.-S., Kim, S., Park, S.-H., Ishibashi, H.: 2016, The 17 March 2015 storm: The associated magnetic flux rope structure and the storm development, Earth, Planets Space, 68, 173, DOI: 10.1186/s40623-016-0551-9.

- Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent
Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.

- Webb, D., N. Nitta: 2017, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.

09/11/2014 23:00:00 UTC

2017-03-06T18:23:06Z

Davidwebb: /* References */

=Comment Section=
*Weak shock arrival on the 11th, with another stronger shock apparent around 15:00 UT on the 12th. These are followed by a strong magnetic field and velocity enhancement, that show indications of magnetic field rotation and expansion. Very strong magnetic field, but very little of it was pointed southward (Hess)

=Image Data=
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2014091100.png|350px]]
[[File:plot_sw_mag_2014091100.png|400px]]
[[File:plot_sw_vel_2014091100.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

=Video Data=

=References=

*McKenna-Lawlor, S., W. Ip, B. Jackson, D. Odstrcil, P. Nieminen, H. Evans, J. Burch, K. Mandt, R. Goldstein, I. Richter, M. Dryer: 2016, Space Weather at Comet 67P/Churyumov–Gerasimenko Before its Perihelion, Earth Moon & Planets, 117, 1–22, DOI 10.1007/s11038-015-9479-5
*Zhao, J., Gilchrist, S.A., Aulanier, G., Schmieder, B., Pariat, E. and Li, H., Hooked flare ribbons and flux-rope related QSL footprints, ApJ, 823 62, DOI http://dx.doi.org/10.3847/0004-637X/823/1/62 (2016).
*Dudik, J., Polito, V., Janvier, M., Mulay, S.M., Karlicky, M., Aulanier, G., Del Zanna, G., Dzifcakova, E., Mason, H.E. and Schmieder, B., Slipping Magnetic Reconnection, Chromospheric Evaporation, Implosion, and Precursors in the 2014 September 10 X1.6-Class Solar Flare, ApJ, 823 41, DOI http://dx.doi.org/10.3847/0004-637X/823/1/41 (2016).
*Webb, D., N. Nitta, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.
*Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.

07/23/2012 23:00:00 UTC

2017-03-06T18:18:59Z

Davidwebb:

This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

[Added by D. Webb]

- M. Temmer: A key element for the extreme character of the July 23, 2012 eruption is a high level of flare energy release over a long time range (max acceleration 2.2km/s^2, ~30 minutes of acceleration phase). Due to an efficient magnetic reconnection process the CME might reach a very high speed (max v=2580+/-280km/s derived from GCS 3D model) that is sustained by the prolonged energy release. The underlying mechanism which is able to build up the energy in the source region as well its conversion into such high kinetic energy is beyond the limit of information from observational data. We encourage modelers to provide further insight into the physics of source regions and reconnection processes related to such extreme events. The very high mass of the CME (1.5x10^16 g) as well as the reduced solar wind density in IP space (1-2/cm^3) due to A) the prior CME from July 19, 2012, B) general low density owing to the low solar activity, may have been the decisive factors for making this event super-fast. In addition, the largely radial orientation of the interplanetary magnetic field, due to its stretching by the CME from July 19, may have reduced the pile-up of solar wind and delayed its replenishment. [Temmer and Nitta, Solar Physics, under review]

REFERENCES:

*Russell, C. et al., ApJ, 770, 38, 2013
*Ngwira, C. et al., GRL, 2013
*Baker, D., Space Weather, 11, 585, 2013
*Liu, D.L. et al., Nature Comm., 5, 4381, 2014.
*Gopalswamy et al., E,P&S, 66, 104, 2014
*Temmer and Nitta, Solar Phys., 290, 919, 2015
*Liou, K, C.-C. Wu, M. Dryer, S.-T. Wu, N. Rich, S. Plunkett, L. Simpson, C. D. Fry, and K. Schenk, Global Hybrid Simulation of Extremely Fast Coronal Mass Ejection on 23 July 2012, JASTP, 121, 32-41, 2014.

03/17/2013 05:30:00 UTC

2017-03-06T18:13:29Z

Davidwebb: /* References */

=Comment Section=
*This is a varSITI campaign event for ISEST and SPeCIMEN.

At the Sun the event had an M1.1 flare, erupting filament, type IV radio burst, fast halo CME. At Earth a shock, possible MC, SEP, and strong storm, Dst=-132. A TB case. Modeled by C-C Wu. [Added by D. Webb]

*Depressed density and temperature as well as decreasing velocity are indicative of a flux rope, but with the weak magnetic field it may just be the flank passing through the Earth. Clear shock signatures in temperature and velocity and total B, more of a gradual increase in density. (Hess)

*The CME propagation from Sun to Earth can be very well modeled with ElEvo (see eps plot below). This CME should have impacted Messenger at Mercury (at least with the shock) on early March 16; MESSENGER/Mercury are roughly 30 degrees west of the Sun-Earth line. (Moestl)
*I used the ElEvo model for the interplanetary shock propagation (Moestl et al. 2015 Nat. Comm.) with initial CME parameters of

launch time: March 15 2013 1100 UT
speed: 1063 km/s at distance 25 Rs
direction: W5 => this is the average of interplanetary directions by HI SSEF modeling from STEREO A and B, taken from the STEREO HI CME catalogue
http://www.helcats-fp7.eu/catalogues/wp3_cat.html CME ids: HCME_B__20130315_01 HCME_A__20130315_02

ElEvo yields an arrival time at the Earth consistent with the observed one, with a drag parameter that is 0.11 (which is slightly lower than average) and a background solar wind of 400 km/s (=normal value).

The predicted speed by ElEvo of about 700 km/s is perfectly consistent with the ICME sheath speed in situ.
In summary, this is a very clear Sun-Earth connection event. (Moestl)

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2013031600.png|350px]]
[[File:plot_sw_mag_2013031600.png|400px]]
[[File:plot_sw_vel_2013031600.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

==Interplanetary propagation==
[[File:elevo_2013_march.eps|400px]]

==Heliospheric Imager Data==
[[File:20120315stereoa.gif]]
[[File:20120315stereob.gif]]

=Video Data=
[http://solar.gmu.edu/wiki/upload/phess4/20120315aia171.mp4 AIA 171] 
[http://solar.gmu.edu/wiki/upload/phess4/20120315aia193.mp4 AIA 193] 
[http://solar.gmu.edu/wiki/upload/phess4/20120315hmi.mp4 HMI] 

=References=

*Wu, Chin-Chun, Kan Liou, Angelos Vourlidas, Simon Plunkett, Murray Dryer, S. T. Wu,
and Richard A. Mewald, Global Magnetohydrodynamic Simulation of the March 15, 2013 Coronal Mass Ejection Event - Interpretation of the 30-80 Mev Proton Flux, JGR, 121, doi:10.1002/2015JA021051, 2016.
*Wu, Chin-Chun, Kan Liou, S. T. Wu, Murray Dryer, and Simon Plunkett, Radial Dependence of Solar Energetic Particles Derived from the 15 March 2013 Solar Energetic Particle Event and Global MHD Simulation, in Proceedings of Solar Wind 14, held in Shandong University, 22-26 June 2015, AIP Conf. Proc. 1720, 070008, doi: 10.1063/1.4943845, 2016. http://scitation.aip.org/content/aip/proceeding/aipcp/10.1063/1.4943845.

03/08/2012 11:00:00 UTC

2017-03-06T18:02:45Z

Davidwebb: /* References */

=Comment Section=
*A fair ICME event, but strong solar source
**X1 flare, fast CME, originated from the eastern hemisphere (~N18E42)
**Solar wind plasma data is corrupted.

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2012030800.png|350px]]
[[File:plot_sw_mag_2012030800.png|400px]]
[[File:plot_sw_vel_2012030800.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

==GOES X-RAY FLUX==
[[File:20120305_goes.png|500px]] 
The GOES X-ray Flux of the flare associated with the event. The vertical line approximately denotes the flare peak time. 

=Video Data=

=References=

*Wang, R., Liu, Y. D., Yang, Z., and Hu, H., Magnetic Field Restructuring Associated with Two Successive Solar Eruptions, 2014, Astrophys. J., 791, 84 (http://iopscience.iop.org/article/10.1088/0004-637X/791/2/84/pdf)
*Liu, Y. D., Luhmann, J. G., Lugaz, N., Möstl, C., Davies, J. A., Bale, S. D., and Lin, R. P., On Sun-to-Earth Propagation of Coronal Mass Ejections, 2013, Astrophys. J., 769, 45 (http://iopscience.iop.org/article/10.1088/0004-637X/769/1/45/pdf)
*Liu, Y. D., Richardson, J. D., Wang, C., and Luhmann, J. G., Propagation of the 2012 March Coronal Mass Ejections from the Sun to Heliopause, 2014, Astrophys. J. Lett., 788, L28 (http://iopscience.iop.org/article/10.1088/2041-8205/788/2/L28/pdf)
*Wood, B. E., J. L. Lean, S. E. McDonald, and Y.-M. Wang (2016), Comparative ionospheric impacts and solar origins of nine strong geomagnetic storms in 2010–2015, J. Geophys. Res., 121, 4938–4965, doi:10.1002/2015JA021953.
*Patsourakos, S. et al., The Major Geoeffective Solar Eruptions of 2012 March 7: Comprehensive Sun-To-Earth Analysis, Astrophys. J., 817, 14, 2016

03/08/2012 11:00:00 UTC

2017-03-06T18:02:12Z

Davidwebb: /* References */

=Comment Section=
*A fair ICME event, but strong solar source
**X1 flare, fast CME, originated from the eastern hemisphere (~N18E42)
**Solar wind plasma data is corrupted.

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2012030800.png|350px]]
[[File:plot_sw_mag_2012030800.png|400px]]
[[File:plot_sw_vel_2012030800.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

==GOES X-RAY FLUX==
[[File:20120305_goes.png|500px]] 
The GOES X-ray Flux of the flare associated with the event. The vertical line approximately denotes the flare peak time. 

=Video Data=

=References=

- Wang, R., Liu, Y. D., Yang, Z., and Hu, H., Magnetic Field Restructuring Associated with Two Successive Solar Eruptions, 2014, Astrophys. J., 791, 84 (http://iopscience.iop.org/article/10.1088/0004-637X/791/2/84/pdf)
- Liu, Y. D., Luhmann, J. G., Lugaz, N., Möstl, C., Davies, J. A., Bale, S. D., and Lin, R. P., On Sun-to-Earth Propagation of Coronal Mass Ejections, 2013, Astrophys. J., 769, 45 (http://iopscience.iop.org/article/10.1088/0004-637X/769/1/45/pdf)
- Liu, Y. D., Richardson, J. D., Wang, C., and Luhmann, J. G., Propagation of the 2012 March Coronal Mass Ejections from the Sun to Heliopause, 2014, Astrophys. J. Lett., 788, L28 (http://iopscience.iop.org/article/10.1088/2041-8205/788/2/L28/pdf)
- Wood, B. E., J. L. Lean, S. E. McDonald, and Y.-M. Wang (2016), Comparative ionospheric impacts and solar origins of nine strong geomagnetic storms in 2010–2015, J. Geophys. Res., 121, 4938–4965, doi:10.1002/2015JA021953.
- Patsourakos, S. et al., The Major Geoeffective Solar Eruptions of 2012 March 7: Comprehensive Sun-To-Earth Analysis, Astrophys. J., 817, 14, 2016

05/31/2013 15:30:00 UTC

2017-03-02T23:51:07Z

Davidwebb: /* References */

=Comment Section=
*This is a varSITI campaign event for ISEST and ROSMIC.

* M. Temmer >> question: CME? or rather CIR which caused the intense geomagnetic storm of -125 nT?
I put together some discussion extracted from the email conversation during June 2 to June 6, 2013. If you were not involved and would be interested in receiving the original emails let me know and I will forward them...

Jie Zhang: I believe that the slow/gradual May 27 CME is the cause of the intense geomagnetic storm. The CME in LASCO is not even close to a typical halo CME (JAVA movie in SEEDS: http://spaceweather.gmu.edu/seeds/dailymkmovie_ql.php?cme=20130527 ). The extremely faint arm across the equator at a later time indicates a partial halo nature. But as pointed out by Nariaki, it would have been regarded as a backside event, due to the lack of surface signature.

Dave Webb: I agree this looks like a great candidate for ISEST study. One reason for the lack of consensus may be that the CME/ICME would have passed mostly north of the ecliptic as evidenced by the COR movies. Note that the ACE data show only brief, but intense southward field after the weak shock. Bernie’s IPS and the HI data should help nail this down. Remember also the slow June 2008 event which was deemed a “stealth” or problem CME even with the STEREO obs. (it hit ST-B, not L1).

Manuela Temmer: There was a big CH on May 29, 2013 from which a solar wind flow at 1AU of 750km/s was estimated (see [http://www.uni-graz.at/~temmerma/download/varsiti/2013May31_CH.png] and [http://www.uni-graz.at/~temmerma/download/varsiti/2013May31_SW.png]). The high-speed stream from the CH might have increased the geo-effectiveness of the CME.

Bothmer Volker: I have been reluctant to comment on this earlier, but the in-situ data Show a classic CIR with sector boundary. No Need for CME search. Textbook CIR storm. Forward Shocks from HSS at 1Au are not so frequent but they occur.

Dave Webb: I tend to agree with Volker B.; I had noted the distinct sector boundary right away. However, I am somewhat reluctant to put this to bed yet. First, the Dst>-100 nT is at the outer limits of what CIRs by themselves can produce (see, eg, Richardson, I.G. et al., JGR, 111, A07S09, 2006). The Dst is mostly driven by the very narrow, brief, strong Bsouth spike at early on June 1. And as earlier posts noted, there are several CME candidates, albeit weak, during this period that could have been compressed by the HSS. CMEs can erupt through the HCS and get caught up at sector boundaries. Is there evidence of ICME flow around this time (I again attach the ACE data plot)? There is the shock, and enhanced density and low T. There are also some rotations in the IMF which was enhanced for >1 day. What do others think about this?

Janet Luhmann: [...] The key to the larger storm is of course the big -Bz that came with the June passage. This is about as big as a CIR storm can get from what I have read. Also although there may not be a CME involved there could of course be some small transients (blobs or slow CME for ex.) that help
make the Bz large-though some of it must arise from the standard CIR velocity deflections.

Ian Richardson: I tend to agree with Volker that this is a classic CIR with what looks like forward (5/31~18 UT) and reverse (6/2~02 UT) shocks (or developing shocks; I haven't looked at any high resolution data), and evidence of a stream interface (e.g., the increase in speed, temperature, decrease in density at 6/1~08 UT) within the CIR , preceded by the already noted sector boundary. The slow-fast stream speed difference is quite large ~300-800 km/s, so this may account for the well formed CIR. Here is a schematic of a CIR after Belcher and Davis 1971, with additions [http://www.uni-graz.at/~temmerma/download/varsiti/2013May31_Ian.png]. [...]

Angelos Vourlidas: I’ve been trying to locate the source region of the CME on May 27th since Jie and Nariaki started discussing this. It is actually a polar CME (only occurring during polarity reversal periods) of streamer-blowout type with a considerable extent towards the ecliptic. Very faint. This event is Earth-directed and there’s some evidence in the in-situ data of multiple fronts encountering Earth between May 30-June 1st. The same can be seen in HI1-A images.

So my proposed interpretation based on Volker’s and Ian’s comments is the following:
We’re seeing the interaction of a fast stream form the CH to the east with the May 27th post-CME flow. That flow (which admittedly is hard to see in regular images. You have to take my word on this at the moment) is likely coming from the area north of AR 11755. There’s a faint filament eruption from that QS neutral line on 5/27 ~9:36UT. So, there’s possibly organized magnetic field structure there which could be compressed in the CIR.

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2013053100.png|350px]]
[[File:plot_sw_mag_2013053100.png|400px]]
[[File:plot_sw_vel_2013053100.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

=Video Data=

=References=
*Gopalswamy, N., Tsurutani, B., Yan, Y.: 2015, Short-term variability of the Sun-Earth system: An overview of progress made during the CAWSES-II period, Progress in Earth and Planetary Sci., 2, 13, DOI 10.1186/s40645-015-0043-8
*Nitta, N. V., T. Mulligan: 2017, Earth-Affecting Coronal Mass Ejections Without Obvious Low Coronal Signatures, Solar Phys., submitted.
*Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.
*Webb, D, N. Nitta: 2017, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.

09/11/2014 23:00:00 UTC

2017-03-02T23:46:11Z

Davidwebb: /* References */

10/08/2012 05:00:00 UTC

2017-03-02T23:43:08Z

Davidwebb: /* References */

=Comment Section=
*This is a varSITI campaign event
*A good ICME, strong CME source, however, "stealth" surface signature (J. Zhang)
**A good example of "stealth" CME: bright CME, but no or very weak surface signature (in terms of no flare, dimming, filament eruption etc)
*This event has a very difficult to distinguish source region, if you look very closely at S22 W38 just before 00:00 UT on the 10/05 it is possible to see a very small disturbance on the Sun, especially in 304 Angstroms. (Hess)
* M. Temmer: clear on-disk signatures - movie from SDO - are visible. It is a "silent" CME, hard to catch for space weather forecasters, but not a "stealth" in sense of no solar surface signatures at all.
http://sdowww.lmsal.com/sdomedia/SunInTime/2012/10/04/daily_211-193-171.mov [October 4, 15UT, central south]

I put some images showing clear coronal restructuring and some discussion points under> http://www.uni-graz.at/~temmerma/download/varsiti/
*C. Moestl: looking at the whole October 4 SDO movie, there are also two other minor eruptions which I find very hard to distinguish from the 15 UT one (1. 7 UT, slightly west of disk center; 2. 0930 UT, south-east quadrant)
* timing - evolution from SDO FoV to coronagraph - is an issue and needs to be looked at in detail
* these eruptions are also visible in the SWAP data (http://proba2.oma.be/), including another minor one at 14h UT in the south-east quadrant (A. Devos)
*Discussion in USTC-China ISEST Workshop on April 19, 2014
**Inferred from GCS model based on STEREO/A, STEREO/B and SOHO coronagraphs, longitude W11 deg, latitude S20 degree
**Around this position, there was a minor activity from 14 to 15 UT on Oct. 14 seen in SDO AIA 193 images. The activity appeared as a weak dimming followed by a diffuse brightening.
**In EUVI-A 195, from 22 UT on Oct. 14, there was a very faint eruption above the south-east limb. This beyond-limb faint eruption is consistent with the heliospheric position of W11S20.
**The CME continued to accelerate to about 10 Rs with a peak speed of 800 km/s at 06 UT, Oct. 15.
**If the eruption started at 14 UT, Oct. 14, it took a long time (10 hrs) for the eruption to reach the COR1 FOV. It indicates that the eruption has a long-lasting low-speed low-acceleration phase

At Earth it produced a small storm, Dst=-105. Electron acceleration in the radiation belt has been measured by the Van Allen Probes and studied by Reeves, et al (2013), Thorne et al. (2013, and Kurita et al. (2016). studied by Reeves, G.D. et al (2013). [Added by D. Webb]

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2012100700.png|350px]]
[[File:plot_sw_mag_2012100700.png|400px]]
[[File:plot_sw_vel_2012100700.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

==Jmaps==
Jmaps from STEREO A and B along the CME leading edge position angle 

[[File:jmapA20101005.jpg|500px]]
[[File:jmapB20101005.jpg|500px]]

 

==Heliospheric Imager Data==
[[File:20121008stereoa.gif]]
[[File:20121008stereob.gif]]

=Video Data=
[http://solar.gmu.edu/wiki/upload/phess4/20121008aia171.mp4 AIA 171] 
[http://solar.gmu.edu/wiki/upload/phess4/20121008aia193.mp4 AIA 193] 
[http://solar.gmu.edu/wiki/upload/phess4/20121008aia304.mp4 AIA 304] 
[http://solar.gmu.edu/wiki/upload/phess4/aia3041005.avi AIA 304 Running Difference Movie] 
[http://solar.gmu.edu/wiki/upload/phess4/aia1931005.avi AIA 195 Running Difference Movie] 
[http://solar.gmu.edu/wiki/upload/phess4/euvi1005.avi STEREO EUVIA 304] 
[http://solar.gmu.edu/wiki/upload/phess4/cor2A1005_good.avi STEREO COR2A] 
[http://solar.gmu.edu/wiki/upload/phess4/cor2B1005_good.avi STEREO COR2B] 
[http://solar.gmu.edu/wiki/upload/phess4/hi1A1005.avi STEREO HI1A] 
[http://solar.gmu.edu/wiki/upload/phess4/hi1b1005.avi STEREO HI1B] 
[http://solar.gmu.edu/wiki/upload/phess4/hi2A1005.avi STEREO HI2A] 
[http://solar.gmu.edu/wiki/upload/phess4/hi2b1005.avi STEREO HI2B] 
[http://solar.gmu.edu/wiki/upload/Adevos/20121004_swap_movie.mp4 PROBA2 SWAP 174] 
[http://solar.gmu.edu/wiki/upload/Adevos/20121004_swap_diff.mp4 PROBA2 SWAP 174 Difference Movie] 

=References=
*Reeves, G. D., et al. (2013), Electron acceleration in the heart of the Van Allen radiation belts, Science, 341(6149), 991–994, doi:10.1126/science.1237743.
*Thorne, R. M., et al. (2013), Rapid acceleration of relativistic radiation belt electrons by magnetospheric chorus, Nature, 504, 411–414, doi:10.1038/nature12889.
*Kurita, S., Y. Miyoshi, J. B. Blake, G. D. Reeves, and C. A. Kletzing (2016), Relativistic electron microbursts and variations in trapped MeV electron fluxes during the 8–9 October 2012 storm: SAMPEX and Van Allen Probes observations, Geophys. Res. Lett., 43, 3017–3025, doi:10.1002/2016GL068260.
*Webb, D., N. Nitta: 2017, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.
*Nitta, N. V., T. Mulligan: 2017, Earth-Affecting Coronal Mass Ejections Without Obvious Low Coronal Signatures, Solar Phys., submitted.
*Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.

07/14/2012 17:00:00 UTC

2017-03-02T23:41:01Z

Davidwebb: /* References */

=Comment Section=
*This is a varSITI campaign event
*A perfect CME-ICME chain event (J. Zhang)
**classical ICME feature: shock + sheath + magnetic cloud
**strong solar signature: X1 flare (S17W08); halo CME, fast and bright
*Propagation Direction is very close to the Sun Earth Line, making this a good event for comparing observations nearer the Sun to in-situ signatures (P. Hess)
*Time Line (2014/04/18, Jie Zhang)
**07/12 15:37 UT: Flare onset; 0 hr
**07/12 16:49 UT: Flare peak (X1.4, S13S03, AR1520); 1 hr 12 min
**07/12 16:48 UT: CME first appear in C2; 1 hr 11 min
**07/12 18:54 UT: CME at 20 Rs; 3 hr 17 min
**07/13 00:49 UT: CME at 50 Rs; 9 hr 12 min
**07/13 06:49 UT: CME at 80 Rs; 15 hr 12 min
**07/14 17:00 UT: Shock arrival at 1 AU; 49 hr 23 min
**07/15 06:00 UT: Magnetic Cloud arrival at 1 AU; 62 hr 23 min
**07/15 19:00 UT: Peak time of Dst (-127 nT); 75 hr 23 min
**07/17 14:00 UT: Magnetic Cloud end at 1 AU; 118 hr 23 min

*04/17 Discussion in Hefei-China workshop
** There are possible two ejecta. The insitu data and Flux rope fitting could be found in the section of in-situ data from Wind below (2014/04/18, Yuming Wang)

*The event produced an intense geomagnetic storm, Dst = -127nT. [added by D. Webb]

*Brigitte Schmieder and her group are working on the solar aspects of this event. They are developing a data-driven simulation to explain the onset of this event and interpret the coronal signatures observed in Dudik et al., 2014. The nlfff extrapolation code is CFITS (Wheatland- Gilchrist) and the simulation is OHM (MHD code of Guillaume Aulanier et al., 2010). They will inform the group of progress. [added by D. Webb]

=Image Data=
==In-Situ Data from Wind==
(Edited by Yuming Wang, 2014/04/18)

Two ejecta are possible.

[[File:overall.jpg|300px]]
[[File:ejectal.jpg|300px]]
[[File:ejecta2.jpg|300px]]

** The fitted coefficients of ejecta 1 are:
*** B0 = 52.098665 nT
*** R = 0.28131624 AU
*** Theta = -45.039456 deg
*** Phi = 150.04089 deg
*** H = 1.0000000
*** d = -0.88881733
*** t_cen = 15-Jul-2012 17:57:21 UT
*** v_x = -547.26224 km/s
*** v_y = -200.49954 km/s
*** v_z = -36.381346 km/s
*** v_exp = 226.05119 km/s, [200.91822, 225.96896]

** The fitted coefficients of ejecta 2 are:
*** B0 = 16.776497 nT
*** R = 0.056126660 AU
*** Theta = -16.776502 deg
*** Phi = 332.51921 deg
*** H = -1.0000000
*** d = -0.81328377
*** t_cen = 16-Jul-2012 20:41:59 UT
*** v_x = -420.51633 km/s
*** v_y = -20.269702 km/s
*** v_z = 26.046412 km/s
*** v_exp = 9.9780682 km/s, [8.1150009, 9.9576277]

==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2012071400.png|350px]]
[[File:plot_sw_mag_2012071400.png|400px]]
[[File:plot_sw_vel_2012071400.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock. 

 
The results from geometrical modeling (speeds and arrival times) in comparison to the in situ data from the Wind spacecraft (C. Moestl). The magnetic cloud is of ESW type (right handed), with the flux rope axis pointing southward; the MC has very long duration (48 hours). The shock arrival time is 2012 July 14 17:38 UT. 

[[File:Data_july122012.png|500px]]
 

== Heliospheric Imaging ==
CME track observed in STEREO-A Jmap with SATPLOT software: (C. Moestl) 
[[File:satplot_jmap_july122012.png|400px]] 
results of geometrical modeling (C. Moestl): 
[[File:Geometry_12_july2012.jpeg‎|400px]] 

Jmaps along the CME leading edge position (about <math>7^{\circ}</math> S of the ecliptic) from STEREO A and B
[[File:20120712JmapA.png|500 px]] [[File:20120712JmapB.png|500 px]] 

De-projected Height Time Plots of the shock and ejecta fronts as obtained from the GCS (measured by Hess) (for GCS details, see Thernisien 2006) along with velocity and acceleration profiles determined from the Aerodynamic Drag Model.

[[File:20120712stack.png]] 

Fitting parameters in GCS Model: Carrington Longitude: 80.5738 degrees, Latitude: -8.9442 degrees, Tilt Angle: 58.1364 degrees, Aspect Ratio: .437363, Half Angular Width: 31.8636 

[[File:20120712stereoa.gif]]
[[File:20120712stereob.gif]]

==Flare Data==
*[[File:eve_flare_2012_07_12.pdf]] EVE and GOES flare profiles
*Flare detection and brightness profile (double peak) by Solar Demon (joint product of AFFECTS and COMESEP FP7 projects) using SDO/AIA 94 [http://solardemon.oma.be/science/flares_details.php?delay=100&clip=1&flare_id=2989]

*GOES X-RAY FLUX
[[File:20120712_goes.png|500px]] 
The GOES X-ray Flux of the flare associated with the event. The vertical line approximately denotes the flare peak time. 

=Video Data=
==SDO observations==
[http://solar.gmu.edu/wiki/upload/enif/aia_12072012_94.avi AIA-94] 
[http://solar.gmu.edu/wiki/upload/JieZhang/20120712_1600-1730_AIA_171.mp4 AIA-171] 
[http://solar.gmu.edu/wiki/upload/enif/aia_12072012_211.avi AIA-211] 
[http://solar.gmu.edu/wiki/upload/JieZhang/20120712_1600-1730_HMI_B.mp4 HMI B] 

==STEREO observations==
[http://solar.gmu.edu/wiki/upload/phess4/cor2A.avi COR2A] 
[http://solar.gmu.edu/wiki/upload/phess4/cor2B.avi COR2B] 
[http://solar.gmu.edu/wiki/upload/phess4/hi1Ard.avi HI1A] 
[http://solar.gmu.edu/wiki/upload/phess4/hi1Brd.avi HI1B] 
[http://solar.gmu.edu/wiki/upload/phess4/hi2Ard.avi HI2A] 
[http://solar.gmu.edu/wiki/upload/phess4/hi2Brd.avi HI2B] 

==PROBA2 observations==
[http://solar.gmu.edu/wiki/upload/Adevos/20120712_swap_movie.mp4 PROBA2 SWAP 174] 
[http://solar.gmu.edu/wiki/upload/Adevos/20120712_swap_diff.mp4 PROBA2 SWAP 174 Difference Movie] 

=References=
(Collected by Xin Cheng and Dave Webb)

1. Dudik, J. et al., ApJ, 2014,[http://adsabs.harvard.edu/abs/2014ApJ...784..144D Slipping Magnetic Reconnection during an X-class Solar Flare Observed by SDO/AIA]

2. Cheng, X. et al., ApJ, 2014,[http://adsabs.harvard.edu/abs/2014arXiv1405.4923C Formation of a Double-decker Magnetic Flux Rope in the Sigmoidal Solar Active Region 11520]

3. Moestl, C. et al., Connecting speeds, directions and arrival times of 22 coronal mass ejections from the Sun to 1 AU, ApJ, 787, 119, 2014

4. Hess, Phillip & Zhang, Jie, ApJ, 792, 49, 2014,[http://adsabs.harvard.edu/abs/2014ApJ...792...49H Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times]

5. Shen, F. et al., JGR, 119, 7128, 2014

6. Wang, R.; Liu, Y. D.; Wiegelmann, T.; Cheng, X.; Hu, H.; Yang, Z., Relationship between Sunspot Rotation and a Major Solar Eruption on 2012 July 12, Solar Phys., DOI: 10.1007/s11207-016-0881-6, 2016.

7. Hu, H., Liu, Y.D., Wang, R., Möstl, C., Yang, Z.: 2016, Sun-To-Earth Characteristics of the 2012 July 12 Coronal Mass Ejection and Associated Geo-Effectiveness, Astrophys. J., 829, 97, doi:10.3847/0004-637X/829/2/97.

8. Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.

9. Gopalswamy, N., Mäkelä, P., Xie, H., Yashiro, S.: 2013,Testing the empirical shock arrival model using quadrature observations, Space Weather, 11, 661–669, doi:10.1002/2013SW000945.

10. Webb, D., N. Nitta: 2017, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.

03/17/2015 04:00:00 UTC

2017-03-02T23:40:08Z

Davidwebb: /* References */

=Comment Section=
*varSITI campaign event
*Largest geomagnetic storm at Earth for solar cycle 24, this event registered a Dst peak of -228 nT.
*Based on both the in-situ signature of the event and the ENLIL solar wind prediction for this date, I think it is likely a CIR played a role in making it so strong. There is a strong coronal hole at the South Pole and the ENLIL simulation ([[http://helioweather.net/archive/2015/03/cmes201503_vel3r2e1b.mp4]]) shows a fairly fast stream that interacts with the CME, and this fast speed stream (~600 km/s) shows up in ACE data as well. Based on the C2 and C3 images for the day, it appears there is a slow CME launching around noon on the 14th with a small but visible filament. On the morning of the 15th a partial halo CME, associated with a long duration flare that fell just short of M class (C9.1) and from the same active region (AR 12297), launched propagating to the East of the Sun Earth line. I think it is likely that an interaction between the CME+shock of this event and the previous blob CME, as well as the added energy from the CIR and fast speed stream behind the CME caused the severity of the geomagnetic activity at the Earth (Hess)
*This super storm is produced through a combination of effects: (1) strong magnetic field in the sheath region (> 25 nT at peak)) and ejecta (>30 nT at peak, (2) Bs field encompasses the entire duration of the ejecta, due to that the axis of the flux rope is highly inclined toward the north-south direction, (3) the interaction with CIR, and almost contained in a CIR region. Such containment by CIR prevents the expansion of the flux rope, thus makes the flux rope small in size by strong in magnetic field (Jie Zhang).
*This may be a kind of CME-CME interaction event. We have a large filament, embedded in a magnetic flux rope, close to the AR which released this highly geoeffective CME. Part of the filament (or flux rope) erupted - or at least, left the low corona - already on March 14 (around 12UT). The final and major eruption on March 15 seems to interact with the first disturbance. The interacting sectors might propagate close to Earth direction. This might be a reason for the complex in-situ signatures (two flux ropes?) as well as the increased geoeffectiveness (Manuela Temmer).
*I was looking at the structure of the ejecta using the Grad-Shafranov reconstruction method. What amazes me is that the cloud can be reconstructed fairly well by the technique despite the magnetic field fluctuations. The reconstruction shows two flux ropes, which is consistent with two interacting CMEs seen in the coronagraph images. (Ling Liu)
*With the ElEvo model results for the March 15 04:00 UT CME shock propagation from Sun to Earth, I need a quite low value of gamma to get the Wind speed and arrival time right, which reflects that this CME did not seem to experience much drag during interplanetary propagation. If the CME apex is really about 40° away from the Earth (as indicated by the source region position), I think its very surprising that Earth is hit by the flux rope. I think this is only possible if the flux rope had a very low inclination to the ecliptic, or as said before that there was some interaction with the CME on March 14. Maybe the drag parameter is low because the CIR was pushing from behind, adding an additional force? (Christian Moestl)
*For Christian's high inclination problem, I think that an explanation is the deflection. My theory proposed that fast CMEs deflect toward east and slow CMEs deflect toward west (Wang et al., JGR, 119, 5117, 2014). Also there are in situ signatures of such possible deflection. From fitting results of my velocity-modified flux rope model, we find there is significant propagation velocity of the CME at 1 AU which is perpendicular to the Sun-Earth line (in +y direction in GSE coordinates). (Yuming Wang)

=USTC mini workshop discussion[2015/06/12]=

==Initiation near the Sun==

Flare: raise/decay time 58 min / 6 hours

CME: Initial speed ~500 - 1000 km/s

Complex eruption. At least three different filaments involved.

Two smaller ones on the left erupted. The longer one on the right was active but not erupted.

First jet like filament eruption at the time of ~00:38UT produced a short duration C2 flare. Second filament eruption at the time of ~01:15UT (flare onset) produced the long duration C9 flare and the CME.

The source region of the flare/filament was not located near the main neutral line of the strong main bipolar region. It was located on the south west of the main active region.

Strong magnetic field cancellation observed near the source region of the second filament eruption.

There was an extended coronal hole in the south west of the active region which might be the source of the fast stream following the ICME.

==Propagation in the interplanetary space==

There was consensus that CME1 on the March 14 and CME2 on the March 15 were not interacted. There was no evidence of interaction in LASCO C2 and C3 images.

Manuela Temmer: just a comment - from the below given results for the CME speed over the distance range 4-20Rs, we derive a deceleration of -20 to -27 m/s^2. This is a rather high value compared to the average as derived from LASCO CDAW results.
[[File:cme_acceleration_CDAW.png]]

From Phil Hess’s measurements based on the spherical bubble model, the CME speed at 4 Rs near 02:00UT is 1100 km/s. It decelerated to 750 km/s at the 20 Rs at 05:30 UT. The propagation direction of this CME is S11W39.

From the GCS model fitting results done by USTC STEP group, the propagation direction is S11W46.

The speed at 02:00UT was 1000 km/s. When it propagated at 20 Rs near the time of 06:06UT, its speed is 720km/s.

From the USTC’s Ice Cream Cone model’s fitting results, this CME propagated with the speed of 807 km/s in the LASCO field of view. The propagation direction is S10W35. The angular width is 115 degree.

Observed transit time: 51 hours (flare onset to shock arrival) || 57 hours (flare onset to ICME arrival)

Model calculations:

Assume: CME initial speed = 800km/s

Background solar wind speed=500 km/s

Results SPM2 [Zhao et al. JGR, 2014, http://www.spaceweather.ac.cn/groupmodel.php?group=sigma ] 53 hours for shock

DMB [Bojan Vrsnak, http://oh.geof.unizg.hr/DBM/dbm.php]: 57 hours for ICME

Assume: CME initial speed = 800km/s

Background solar wind speed=400 km/s

Results: SPM2[Zhao et al. JGR, 2014, ] 60 hours for shock

DMB[Bojan Vrsnak]: 63 hours for ICME

==In situ properties and geoeffectiveness==

Questions:

What is the connection between the solar and interplanetary observations?

Why this high inclined and not earth directed CME arrived at the Earth?

Why is this a super geomagnetic storm considering the small flare of C9 class and intermediate CME speed of less than 1000 km/s?

Why is the magnetic field irregular? i. e. not a typical magnetic cloud?

==Geospace response==

=Image Data=

==In-situ data==
[[File:20150315_magplasma.png]]
[[File:20150315_mag.png]] 
*These are in-situ plots based on the ACE daily text files, I will update them when the cdf data becomes available. In these plots the shock is very clear, but beyond that any ejecta signature is weak and there does not appear to be any strong Magnetic cloud. But there are two clear and distinct periods of strong -Bz. (Hess)

[[File:WindData.png|600px]]
*Manuela Temmer: Wind in-situ data, and attempt to fit the flux rope (Lundquist model).

==LASCO/Kanzelhöhe==
Image collection of white light and chromospheric data, showing two disturbances and the partly erupted filament which is related to the CME producing AR:
[link http://www.uni-graz.at/~temmerma/download/varsiti/20150315.pdf]

==GOES Plot==
[[File:20150315_goes.png]]

==SOHO/LASO measurement==
[[File:Hess_heights.png|700px]]
*Height-Time plot based on SOHO/LASCO measurement
[[File:Hess_velocity.png|700px]]
*Velocity-Time plot from SOHO/LASCO H-T measurement
*Height-Time measurement data from SOHO/LASCO: [[Hess_measurement.docx]]

measurements from CORIMP (max speed given as 918 km/s, central PA as 262)
http://alshamess.ifa.hawaii.edu/CORIMP/realtime/soho/lasco/detections/2015/03/15/cme_kins/plot_kins_quartiles_savgol_20150315_000006.jpg

== Interplanetary Propagation ==
Christian Möstl and Tanja Rollett:
ElEvo results (parameters already tweaked so it matches Wind arrivals):
shock arrival at Wind: March 17 03:50 UT
arrival speed 665 km/s

Wind observations (taken from the Wu et al. draft):
shock arrival March 17 03:59 UT
arrival speed of the sheath is 500- 600 km/s, about 100 km/s less than the ElEvo arrival speed.

This model/plot can be adjusted very easily if you think the CME initial speed, direction and launch time should be different.

initial CME parameters:
inital speed at 15 Rs: 1120 km/s, at time 2015 March 15 04:00 UT, direction to Earth west 39°
the speed was taken from Kevin Schenk real time email, consistent with Gopalswamy et al. proceeding; same for direction. Thus I assume that the source region position is similar to the CME direction. Because the flare happens inside the AR and there are no large coronal holes nearby, it should be relatively safe to assume this direction as the CME propagation direction. The asymmetric halo with more material to the west of the Sun also supports this. Other Parameters: background wind: 400 km/s, gamma: 0.1, ellipse aspect ratio 1.6, full width: 100° in heliospheric longitude.

We have also experimented with the initial conditions given by the above LASCO measurements for the CME shock, using launch on March 15 08:06 UT, at 28.7 Rs, speed of 700 km/s
but the arrival times we get are about 0.5-1 day to late compared to the observed one at Wind, even with very extreme choices for gamma and the ellipse aspect ratio or a direct propagation towards Earth the observed arrival time is not reproduced. Thus, it seems that the (projected) initial speed is too slow for this event - ElEvo with 1120 km/s initial speed as indicated by the real time measurements is able to reproduce the observed arrival time and speed as shown above.

[[File:elevo_15_mar_2015_storm_small2.png]]

=Video Data=
[http://solar.gmu.edu/wiki/upload/phess4/201503171.gif AIA 171 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503193.gif AIA 193 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503304.gif AIA 304 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/2015031600.gif AIA 1600 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503hmi.gif HMI movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503c2.gif C2 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503c3.gif C3 movie] 
movie from CORIMP catalogue:
http://alshamess.ifa.hawaii.edu/CORIMP/realtime/soho/lasco/detections/2015/03/15/cme_ims_orig_20150315_000006/movie_C3.html

=References=
- ElEvo model: Möstl et al. 2015 Nature Communications, open access: http://www.nature.com/ncomms/2015/150526/ncomms8135/full/ncomms8135.html

- P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf

- Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015.

- Kamide, Y. & K. Kusano, Space Weather, 13, 2015.

- Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.

- Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

- Wang, Y. et al., On the Propagation of a Geoeffective Coronal Mass Ejection during March 15 – 17, 2015, JGR, 121, 7423 (2016).

- Jakosky, B. M., J. M. Grebowsky, J. G. Luhmann, D. A. Brain, Initial results from the MAVEN mission to Mars. Geophys. Res. Lett. 10.1002/2015GL065271 (2015).

- Cherniak, I., I. Zakharenkova, and R. J. Redmon (2015), Dynamics of the high-latitude ionospheric irregularities during the 17 March 2015 St. Patrick’s Day storm: Ground-based GPS measurements, Space Weather, 13, 585–597,doi:10.1002/2015SW001237.

- Le, G., et al. (2016), Magnetopause erosion during the 17 March 2015 magnetic storm: Combined field-aligned currents, auroral oval, and magnetopause observations, GRL, 43, 2396–2404, doi:10.1002/2016GL068257.

- Wood, B. E., J. L. Lean, S. E. McDonald, and Y.-M. Wang (2016), Comparative ionospheric impacts and solar origins of nine strong geomagnetic storms in 2010–2015, J. Geophys. Res., 121, 4938–4965, doi:10.1002/2015JA021953.

- Wu, C.-C., et al., The first super geomagnetic storm of solar cycle 24: “The St. Patrick’s day event (17 March 2015)”, Earth, Planets and Space (2016) 68:151 DOI 10.1186/s40623-016-0525-y.

- Marubashi, K., Cho, K.-S., Kim, R.-S., Kim, S., Park, S.-H., Ishibashi, H.: 2016, The 17 March 2015 storm: The associated magnetic flux rope structure and the storm development, Earth, Planets Space, 68, 173, DOI: 10.1186/s40623-016-0551-9.

- Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent
Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.

- Webb, D., N. Nitta: 2017, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.

06/21/2015 15:30:00 UTC

2017-03-02T23:39:26Z

Davidwebb: /* References */

=Comment Section=
*Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst near -200 (Hess) 

*WG4 EMAIL DISCUSSION ABOUT EVENT:

- July 14, 2015 
This event would perfectly fit as VarSITI Campaign Event. There are a lot of interesting aspects and the observations are quite nice to track the full chain of action and reaction when interacting with Earth (maybe also interesting for other VarSITI projects, e.g. ROSMIC?).
Cheers,
Manuela

This is a very interesting event indeed!

The discussion of multi-step storms reminds me of this 2002 paper. It has discussion on plasma sheet effect on ring current (and Dst) and in particular shows an interesting simulation results where two earlier Bs periods were removed and its effect to the total intensity of the storm studied. It seems that removing the earlier Bs peaks did not affect significantly to the total intensity of the storm.
http://onlinelibrary.wiley.com/doi/10.1029/2001JA000023/full

The strongest Bs intervals and the Dst minimum in the June event are indeed preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have lead to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

greetings,
Emilia

- July 13, 2015 
Hi Dave et al.,

Here is a plot combining Wind data and Dst. This is actually a multi-step
geomagnetic storm with the global minimum of -195 nT. The first dip was
produced by the fluctuating southward field components upstream of the
third shock, the second one by the southward field components downstream
of the third shock, and the major one by the southward field components
within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I
agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious
geo-effectiveness, as you can see from the data. The fourth shock in the
plot was associated with the June 22 M6.5 eruption, and it was beginning
to overtake the ICME from behind at 1 AU. Another eruption on June 25
(M7.9) also produced a shock that impacted Earth (not shown in the plot),
but it didn't produce geo-effectiveness either.

Also we see another 2 proceeding shocks as pointed out by Noe. These
multiple preceding shocks and sheaths may precondition the magnetosphere
for the growth of a strong geomagnetic storm (say, by feeding plasma to
the plasma sheet). I am not sure if the third shock was propagating into a
preceding ejecta, because I don't see clear ICME signatures upstream of
the shock. The fluctuating southward fields upstream of the third shock
may be produced by amplification of the ambient fields by the preceding
shocks.

Best,
Ying

On Mon, July 13, 2015 2:00 pm, Nariaki Nitta wrote:
> Dave,
>
> I normally look for shocks rather than ICMEs on ACE RTSW data. I don't
> think your M6.5 flare (on 22 June) had to do with the big Dst decrease
> during 22-23 June. The CME associated with the M6.5 flare was fast but
> not geo-effective (see
> https://twitter.com/halocme/status/613835532116828160). Different
> thoughts?
>
> Nariaki
>
> David Webb wrote on 13.07.15 13:48:
>
>> Nariaki,
>>
>> Of course I knew you would have it figured out! I guess we all need to
>> get on Twitter- wonder when NOAA will start sending out "official"
>> forecasts via Twitter!! Do I need to be a Twitter "subscriber" to get
>> your tweets?
>>
>> So I assume you ID the 3 CMEs as the shock arrival times. Again let's
>> be careful to differentiate shock from CME/ICME arrivals. Noe is saying
>> that one of the early shocks is propagating thru a preceding CME. And
>> what happened to the M6.5 event? What drove Dst to such low levels?
>>
>> Questions, questions,
>> Dave
>>
>> On Mon, Jul 13, 2015 at 4:29 PM, Nariaki Nitta <nitta@lmsal.com
>> <mailto:nitta@lmsal.com>> wrote:
>>
>> Dave,
>>
>> While you were preparing for SHINE, I tweeted a couple of time on
>> the road (therefore no detailed image analysis). There were at least four
>> eruptions during 18-22 June and the third one (associated with a M2
>> flare on 21 June) was a quite impressively circular CME
>> (https://twitter.com/halocme/status/612498918639677440), which I
>> think contributed the most to the geo-space effects (the CME arrived much
>> earlier than I had thought). Three CMEs seemed to arrive without
>> merging, see https://twitter.com/halocme/status/613216284675821568 (I
>> had to adjust the time axes of the plots). As of 23 June, it looked
>> possible that the Dst may hit -200 nT
>> (https://twitter.com/halocme/status/613227633074028544, indeed
>> auroras in California!). The M6.5 flare on 22 June was not associated
>> with a very geo-effective CME even though it arrived fast.
>>
>> The most recent storm (13 July) was much less impressive, even its
>> origin not being entirely clear.
>>
>> Nariaki
>>

Hi Dave et al.,

The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME, something I have been looking at recently. The larger dip on the 23rd is due to the following CME.
Wind data is attached. There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

Best,
Noé Lugaz

On Jul 13, 2015, at 3:26 PM, David Webb <david.webb@bc.edu> wrote:

Kyoto shows that this storm nearly reached "superstorm" (Dst<-200nT) level.
http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201506/dst1506.png

Many of us may have been distracted with our preparations for SHINE. Manuela first alerted us. Do we understand the cause-effect for it? Tamitha's recent video showed that it had significant geo-effects. There were apparently a series of flares/CMEs/EPs on June 21-22. Probably the storm was driven by the M7 event on June 22 but are we sure; was it a compound event?
-------

=Image Data=
[[File:20150623 satenv.gif]] 

[[File:Ace-mag-swepam-7-day.gif‎]] 

[[File:YL Wind ICMEs 21-25June2015.jpg|500px]] 

Courtesy Ying Liu.

=Video Data=

=References=

*Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, 2015, ApJL, 809, L34 (http://iopscience.iop.org/article/10.1088/2041-8205/809/2/L34/pdf).
*Reiff, P.H., A. G. Daou, S. Y. Sazykin, R. Nakamura, M. R. Hairston, V. Coffey, M. O. Chandler, B. J. Anderson, C. T. Russell, D. Welling, S. A. Fuselier, K. J., Genestretim, Multispacecraft Observations and Modeling of the June 22/23, 2015 Geomagnetic Storm, 2016, GRL, 43, 7311–7318, doi:10.1002/2016GL069154.
*Baker, D. et al., A telescopic and microscopic examination of acceleration in the June 2015 geomagnetic storm:…”, 2016, GRL, 43, 6051.
*Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.
*Manoharan, P.K., Maia, D., Johri, A., Induja, M.S.: 2016, Interplanetary consequences of coronal mass ejections events occurred during 18-25 June 2015. In: Dorotovic, I., Fischer, C.E., Temmer, M. (eds.) Ground-based Solar Observations in the Space Instrumentation Era, ASP Conf. Ser. 504, p. 59.
*Lugaz, N., Farrugia, C. J., Winslow, R. M., Al-Haddad, N., Kilpua, E. K. J., P. Riley: 2016, Factors affecting the geoeffectiveness of shocks and sheaths at 1 AU, J. Geophys. Res., 121, 10,861–10,879, doi:10.1002/2016JA023100.
*Webb, D., N. Nitta: 2017, Study on Understanding Problem Forecasts of ISEST Campaign Flare-CME Events, Solar Phys., submitted.

06/21/2015 15:30:00 UTC

2017-03-02T23:35:30Z

Davidwebb: /* References */

03/17/2015 04:00:00 UTC

2017-03-02T23:32:24Z

Davidwebb: /* References */

=Comment Section=
*varSITI campaign event
*Largest geomagnetic storm at Earth for solar cycle 24, this event registered a Dst peak of -228 nT.
*Based on both the in-situ signature of the event and the ENLIL solar wind prediction for this date, I think it is likely a CIR played a role in making it so strong. There is a strong coronal hole at the South Pole and the ENLIL simulation ([[http://helioweather.net/archive/2015/03/cmes201503_vel3r2e1b.mp4]]) shows a fairly fast stream that interacts with the CME, and this fast speed stream (~600 km/s) shows up in ACE data as well. Based on the C2 and C3 images for the day, it appears there is a slow CME launching around noon on the 14th with a small but visible filament. On the morning of the 15th a partial halo CME, associated with a long duration flare that fell just short of M class (C9.1) and from the same active region (AR 12297), launched propagating to the East of the Sun Earth line. I think it is likely that an interaction between the CME+shock of this event and the previous blob CME, as well as the added energy from the CIR and fast speed stream behind the CME caused the severity of the geomagnetic activity at the Earth (Hess)
*This super storm is produced through a combination of effects: (1) strong magnetic field in the sheath region (> 25 nT at peak)) and ejecta (>30 nT at peak, (2) Bs field encompasses the entire duration of the ejecta, due to that the axis of the flux rope is highly inclined toward the north-south direction, (3) the interaction with CIR, and almost contained in a CIR region. Such containment by CIR prevents the expansion of the flux rope, thus makes the flux rope small in size by strong in magnetic field (Jie Zhang).
*This may be a kind of CME-CME interaction event. We have a large filament, embedded in a magnetic flux rope, close to the AR which released this highly geoeffective CME. Part of the filament (or flux rope) erupted - or at least, left the low corona - already on March 14 (around 12UT). The final and major eruption on March 15 seems to interact with the first disturbance. The interacting sectors might propagate close to Earth direction. This might be a reason for the complex in-situ signatures (two flux ropes?) as well as the increased geoeffectiveness (Manuela Temmer).
*I was looking at the structure of the ejecta using the Grad-Shafranov reconstruction method. What amazes me is that the cloud can be reconstructed fairly well by the technique despite the magnetic field fluctuations. The reconstruction shows two flux ropes, which is consistent with two interacting CMEs seen in the coronagraph images. (Ling Liu)
*With the ElEvo model results for the March 15 04:00 UT CME shock propagation from Sun to Earth, I need a quite low value of gamma to get the Wind speed and arrival time right, which reflects that this CME did not seem to experience much drag during interplanetary propagation. If the CME apex is really about 40° away from the Earth (as indicated by the source region position), I think its very surprising that Earth is hit by the flux rope. I think this is only possible if the flux rope had a very low inclination to the ecliptic, or as said before that there was some interaction with the CME on March 14. Maybe the drag parameter is low because the CIR was pushing from behind, adding an additional force? (Christian Moestl)
*For Christian's high inclination problem, I think that an explanation is the deflection. My theory proposed that fast CMEs deflect toward east and slow CMEs deflect toward west (Wang et al., JGR, 119, 5117, 2014). Also there are in situ signatures of such possible deflection. From fitting results of my velocity-modified flux rope model, we find there is significant propagation velocity of the CME at 1 AU which is perpendicular to the Sun-Earth line (in +y direction in GSE coordinates). (Yuming Wang)

=USTC mini workshop discussion[2015/06/12]=

==Initiation near the Sun==

Flare: raise/decay time 58 min / 6 hours

CME: Initial speed ~500 - 1000 km/s

Complex eruption. At least three different filaments involved.

Two smaller ones on the left erupted. The longer one on the right was active but not erupted.

First jet like filament eruption at the time of ~00:38UT produced a short duration C2 flare. Second filament eruption at the time of ~01:15UT (flare onset) produced the long duration C9 flare and the CME.

The source region of the flare/filament was not located near the main neutral line of the strong main bipolar region. It was located on the south west of the main active region.

Strong magnetic field cancellation observed near the source region of the second filament eruption.

There was an extended coronal hole in the south west of the active region which might be the source of the fast stream following the ICME.

==Propagation in the interplanetary space==

There was consensus that CME1 on the March 14 and CME2 on the March 15 were not interacted. There was no evidence of interaction in LASCO C2 and C3 images.

Manuela Temmer: just a comment - from the below given results for the CME speed over the distance range 4-20Rs, we derive a deceleration of -20 to -27 m/s^2. This is a rather high value compared to the average as derived from LASCO CDAW results.
[[File:cme_acceleration_CDAW.png]]

From Phil Hess’s measurements based on the spherical bubble model, the CME speed at 4 Rs near 02:00UT is 1100 km/s. It decelerated to 750 km/s at the 20 Rs at 05:30 UT. The propagation direction of this CME is S11W39.

From the GCS model fitting results done by USTC STEP group, the propagation direction is S11W46.

The speed at 02:00UT was 1000 km/s. When it propagated at 20 Rs near the time of 06:06UT, its speed is 720km/s.

From the USTC’s Ice Cream Cone model’s fitting results, this CME propagated with the speed of 807 km/s in the LASCO field of view. The propagation direction is S10W35. The angular width is 115 degree.

Observed transit time: 51 hours (flare onset to shock arrival) || 57 hours (flare onset to ICME arrival)

Model calculations:

Assume: CME initial speed = 800km/s

Background solar wind speed=500 km/s

Results SPM2 [Zhao et al. JGR, 2014, http://www.spaceweather.ac.cn/groupmodel.php?group=sigma ] 53 hours for shock

DMB [Bojan Vrsnak, http://oh.geof.unizg.hr/DBM/dbm.php]: 57 hours for ICME

Assume: CME initial speed = 800km/s

Background solar wind speed=400 km/s

Results: SPM2[Zhao et al. JGR, 2014, ] 60 hours for shock

DMB[Bojan Vrsnak]: 63 hours for ICME

==In situ properties and geoeffectiveness==

Questions:

What is the connection between the solar and interplanetary observations?

Why this high inclined and not earth directed CME arrived at the Earth?

Why is this a super geomagnetic storm considering the small flare of C9 class and intermediate CME speed of less than 1000 km/s?

Why is the magnetic field irregular? i. e. not a typical magnetic cloud?

==Geospace response==

=Image Data=

==In-situ data==
[[File:20150315_magplasma.png]]
[[File:20150315_mag.png]] 
*These are in-situ plots based on the ACE daily text files, I will update them when the cdf data becomes available. In these plots the shock is very clear, but beyond that any ejecta signature is weak and there does not appear to be any strong Magnetic cloud. But there are two clear and distinct periods of strong -Bz. (Hess)

[[File:WindData.png|600px]]
*Manuela Temmer: Wind in-situ data, and attempt to fit the flux rope (Lundquist model).

==LASCO/Kanzelhöhe==
Image collection of white light and chromospheric data, showing two disturbances and the partly erupted filament which is related to the CME producing AR:
[link http://www.uni-graz.at/~temmerma/download/varsiti/20150315.pdf]

==GOES Plot==
[[File:20150315_goes.png]]

==SOHO/LASO measurement==
[[File:Hess_heights.png|700px]]
*Height-Time plot based on SOHO/LASCO measurement
[[File:Hess_velocity.png|700px]]
*Velocity-Time plot from SOHO/LASCO H-T measurement
*Height-Time measurement data from SOHO/LASCO: [[Hess_measurement.docx]]

measurements from CORIMP (max speed given as 918 km/s, central PA as 262)
http://alshamess.ifa.hawaii.edu/CORIMP/realtime/soho/lasco/detections/2015/03/15/cme_kins/plot_kins_quartiles_savgol_20150315_000006.jpg

== Interplanetary Propagation ==
Christian Möstl and Tanja Rollett:
ElEvo results (parameters already tweaked so it matches Wind arrivals):
shock arrival at Wind: March 17 03:50 UT
arrival speed 665 km/s

Wind observations (taken from the Wu et al. draft):
shock arrival March 17 03:59 UT
arrival speed of the sheath is 500- 600 km/s, about 100 km/s less than the ElEvo arrival speed.

This model/plot can be adjusted very easily if you think the CME initial speed, direction and launch time should be different.

initial CME parameters:
inital speed at 15 Rs: 1120 km/s, at time 2015 March 15 04:00 UT, direction to Earth west 39°
the speed was taken from Kevin Schenk real time email, consistent with Gopalswamy et al. proceeding; same for direction. Thus I assume that the source region position is similar to the CME direction. Because the flare happens inside the AR and there are no large coronal holes nearby, it should be relatively safe to assume this direction as the CME propagation direction. The asymmetric halo with more material to the west of the Sun also supports this. Other Parameters: background wind: 400 km/s, gamma: 0.1, ellipse aspect ratio 1.6, full width: 100° in heliospheric longitude.

We have also experimented with the initial conditions given by the above LASCO measurements for the CME shock, using launch on March 15 08:06 UT, at 28.7 Rs, speed of 700 km/s
but the arrival times we get are about 0.5-1 day to late compared to the observed one at Wind, even with very extreme choices for gamma and the ellipse aspect ratio or a direct propagation towards Earth the observed arrival time is not reproduced. Thus, it seems that the (projected) initial speed is too slow for this event - ElEvo with 1120 km/s initial speed as indicated by the real time measurements is able to reproduce the observed arrival time and speed as shown above.

[[File:elevo_15_mar_2015_storm_small2.png]]

=Video Data=
[http://solar.gmu.edu/wiki/upload/phess4/201503171.gif AIA 171 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503193.gif AIA 193 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503304.gif AIA 304 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/2015031600.gif AIA 1600 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503hmi.gif HMI movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503c2.gif C2 movie] 
[http://solar.gmu.edu/wiki/upload/phess4/201503c3.gif C3 movie] 
movie from CORIMP catalogue:
http://alshamess.ifa.hawaii.edu/CORIMP/realtime/soho/lasco/detections/2015/03/15/cme_ims_orig_20150315_000006/movie_C3.html

=References=
- ElEvo model: Möstl et al. 2015 Nature Communications, open access: http://www.nature.com/ncomms/2015/150526/ncomms8135/full/ncomms8135.html

- P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf

- Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015.

- Kamide, Y. & K. Kusano, Space Weather, 13, 2015.

- Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.

- Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

- Wang, Y. et al., On the Propagation of a Geoeffective Coronal Mass Ejection during March 15 – 17, 2015, JGR, 121, 7423 (2016).

- Jakosky, B. M., J. M. Grebowsky, J. G. Luhmann, D. A. Brain, Initial results from the MAVEN mission to Mars. Geophys. Res. Lett. 10.1002/2015GL065271 (2015).

- Cherniak, I., I. Zakharenkova, and R. J. Redmon (2015), Dynamics of the high-latitude ionospheric irregularities during the 17 March 2015 St. Patrick’s Day storm: Ground-based GPS measurements, Space Weather, 13, 585–597,doi:10.1002/2015SW001237.

- Le, G., et al. (2016), Magnetopause erosion during the 17 March 2015 magnetic storm: Combined field-aligned currents, auroral oval, and magnetopause observations, GRL, 43, 2396–2404, doi:10.1002/2016GL068257.

- Wood, B. E., J. L. Lean, S. E. McDonald, and Y.-M. Wang (2016), Comparative ionospheric impacts and solar origins of nine strong geomagnetic storms in 2010–2015, J. Geophys. Res., 121, 4938–4965, doi:10.1002/2015JA021953.

- Wu, C.-C., et al., The first super geomagnetic storm of solar cycle 24: “The St. Patrick’s day event (17 March 2015)”, Earth, Planets and Space (2016) 68:151 DOI 10.1186/s40623-016-0525-y.

- Marubashi, K., Cho, K.-S., Kim, R.-S., Kim, S., Park, S.-H., Ishibashi, H.: 2016, The 17 March 2015 storm: The associated magnetic flux rope structure and the storm development, Earth, Planets Space, 68, 173, DOI: 10.1186/s40623-016-0551-9.

- Marubashi, K., K.-S. Cho, H. Ishibashi: 2017, Interplanetary Magnetic Flux Rope as Agent
Connecting Solar Eruptions and Geomagnetic Activities, Solar Phys., submitted.

-

07/14/2012 17:00:00 UTC

2017-03-02T23:28:05Z

Davidwebb: /* References */

09/12/2014 15:26:00 UTC

2017-01-20T22:23:33Z

Davidwebb: /* References */

==Comments==

An X1.6 flare and wave near Sun Center and a nearly symmetric halo CME on Sept. 10. The ICME at L1 on 12-13 Sept., following two IP shocks, mostly had strong northward field in the putative flux rope (several models produced). The southward fields, which drove the early storm activity, were in the sheaths trailing two IP shocks, the second one being the strongest. The ICME north field rapidly shut down the auroral and storm activity.

A STEREO SWx Group event. B. Jackson at UCSD runs a real time forecast site, and have included the Rosetta comet mission in the forecasts, currently using IPS data. A density response at Rosetta due to the Sept. 10 event was predicted for IPS and modeled using the ENLIL 3D-MHD code. We are looking for Rosetta solar wind data to confirm an ICME there.

==Solar Data==

[[File:20140911_xray.gif|400px]]

*GOES X-ray plot showing the X1.6 peak level flare.

[[File:CORIMP 20140910.jpg|500px]]

*Tracking program on CME based on realtime data listed in the CORIMP "Weekly CME detections (past 7 days)" online here: 
http://alshamess.ifa.hawaii.edu/CORIMP 
[From Jason Bryne]

==Heliospheric Data==

*Link to GSFC SWRC Enlil prediction run on Sept. 10 at 11:58 pm. 
http://iswa.gsfc.nasa.gov/ENSEMBLE/2014-09-10_ncmes1_sims18_LIHUE079/20140910_181800_ncmes1_sims18_LIHUE079_anim_tim-den.gif

*This and other CMEs on 9-10 Sept. were tracked out to the Rosetta S/C using IPS-driven 3D tomography and ENLIL modeling as discussed by McKenna-Lawlor et al. (EM&P, subm, 2015).

==In-Situ Data==

[[File:Mag_swe_7d_9sep2014.gif|400px]]

*ACE plasma and magnetic field plots are Sept. 9-15, 2014 showing two shocks at 11, 22:56 UT and 12, 15:26 UT. Southward field in the shock sheaths drives some storminess but Bz in the long duration ICME following the second shock is entirely northward, shutting down the storm activity.

[[File:wind_20140911-14.gif|500px]]

*Nitta's plot of ACE RTSW data in the style of K. Marubashi (http://www.lmsal.com/nitta/outgoing/nrt/plot_sw_mag_ace_rtsw_201409110900_201409142100.gif). The bottom panel suggests that the closest MC type is WNE (RH) in reference to Mulligan, Russell and Luhmann (1999) (http://www.lmsal.com/nitta/outgoing/nrt/mc_mulligan_20140912.png.) For this event people predicted either WSE or SEN with Bz<0, and LH. [Plot from Nariki Nitta on Sept. 15, 2014]

*THE "FORBUSH REBOUND": Radiation levels in the stratosphere are back to normal following a mid-September dip caused by one of the strongest solar storms in years. The story begins three weeks ago. On Sept. 12th a CME hit Earth head-on, sparking a G3-class geomagnetic storm. Using a helium balloon, the students of Earth to Sky Calculus launched a radiation sensor into the storm, expecting to measure an increase in energetic particles. Instead of more, however, they measured less. The CME had swept away many of the cosmic rays around Earth and so radiation levels in the stratosphere dropped.

The CME was long gone on Sept. 28th when they repeated the experiment and found radiation levels returning to pre-storm values.
The drop in radiation is called a "Forbush Decrease" after the 20th century physicist Scott Forbush who first described it. This would make the bounce-back a "Forbush Rebound." According to the data, the rebound took less than two weeks and possibly only a few days. The next time a CME hits, the students plan to launch balloons with a faster cadence to better measure the stratosphere's response time.
The group uses a Space Weather Buoy--an insulated capsule containing an X-ray/gamma-ray detector (10 keV - 20 MeV), multiple video cameras, GPS trackers, and other sensors. The payload went to 108,700 feet above the Death Valley National Park. 
From Spaceweather.com, issue 3 Oct. 2014.

==References==

- McKenna-Lawlor et al. EM&P, 117, 1–22, DOI 10.1007/s11038-015-9479-5, (2016)

- B. Jackson, priv. comm.

- Zhao, J., Gilchrist, S.A., Aulanier, G., Schmieder, B., Pariat, E. and Li, H., Hooked flare ribbons and flux-rope related QSL footprints, ApJ, 823 62, DOI http://dx.doi.org/10.3847/0004-637X/823/1/62 (2016).

- Dudik, J., Polito, V., Janvier, M., Mulay, S.M., Karlicky, M., Aulanier, G., Del Zanna, G., Dzifcakova, E., Mason, H.E. and Schmieder, B., Slipping Magnetic Reconnection, Chromospheric Evaporation, Implosion, and Precursors in the 2014 September 10 X1.6-Class Solar Flare, ApJ, 823 41, DOI http://dx.doi.org/10.3847/0004-637X/823/1/41 (2016).

01/08/2014-01/09/2014

2017-01-20T22:18:47Z

Davidwebb: /* References */

=Comment Section=
*This event has been included because it has a very strong Halo CME entering LASCO around 17:48 UT on the 7th, but presents no obvious in-situ signatures at L1. (Hess)
This is thus a “problem” event and is being studied for an AGU session. N. Gopalswamy reports that the January 6 and 7 CMEs are quite intriguing. The Jan. 6 event produced a GLE even though it had a speed <2000 km/s and originated behind the west limb (Thakur et al., ApJ, 2014). The Jan. 7 CME was near disk center and ultrafast (~3000 km/s), but was likely deflected to the south and west so it was not geoefffective although it was a large SEP event. It was also not a GLE. (D. Webb)

=Image Data=

=Video Data=

=References=

- Thakur et al., ApJ, 790, L13, DOI http://dx.doi.org/10.1088/2041-8205/790/1/L13 (2014).

- Webb, D., An Overview of the 7 January 2014 X-Class Flare-CME and Space Weather Predictions, AGU SH51E-01, 2014.

- Moestl et al., Nat. Commun., 6, 7135, 2015.

- Gopalswamy et al., EP&S, 66, 104, 2014.

- Wang, R., Liu, Y. D., Dai, X., Yang, Z., Huang, C., and Hu, H., The role of active region coronal magnetic field in determining coronal mass ejection propagation direction, 2015, Astrophys. J., 814, 80 (http://iopscience.iop.org/article/10.1088/0004-637X/814/1/80/pdf)

- Mays, M.L., B. J. Thompson, L. K. Jian, R. C. Colaninno, D. Odstrcil, C. Möstl, M. Temmer, N. P. Savani, G. Collinson, A. Taktakishvili, P. J. MacNeice , and Y. Zheng, Propagation of the 2014 January 7 CME and Resulting Geomagnetic Non-Event, Astrophys. J, 812, 145, 2015

01/08/2014-01/09/2014

2017-01-20T22:18:08Z

Davidwebb: /* References */

=Comment Section=
*This event has been included because it has a very strong Halo CME entering LASCO around 17:48 UT on the 7th, but presents no obvious in-situ signatures at L1. (Hess)
This is thus a “problem” event and is being studied for an AGU session. N. Gopalswamy reports that the January 6 and 7 CMEs are quite intriguing. The Jan. 6 event produced a GLE even though it had a speed <2000 km/s and originated behind the west limb (Thakur et al., ApJ, 2014). The Jan. 7 CME was near disk center and ultrafast (~3000 km/s), but was likely deflected to the south and west so it was not geoefffective although it was a large SEP event. It was also not a GLE. (D. Webb)

=Image Data=

=Video Data=

=References=

- Thakur et al., ApJ, 790, L13, DOI http://dx.doi.org/10.1088/2041-8205/790/1/L13 (2014).

- Webb, D., An Overview of the 7 January 2014 X-Class Flare-CME and Space Weather Predictions, AGU SH51E-01, 2014.

- Moestl et al., Nat. Commun., 6, 7135, 2015.

- Gopalswamy et al., E,P&S, 66, 104, 2014.

- Wang, R., Liu, Y. D., Dai, X., Yang, Z., Huang, C., and Hu, H., The role of active region coronal magnetic field in determining coronal mass ejection propagation direction, 2015, Astrophys. J., 814, 80 (http://iopscience.iop.org/article/10.1088/0004-637X/814/1/80/pdf)

- Mays, M.L., B. J. Thompson, L. K. Jian, R. C. Colaninno, D. Odstrcil, C. Möstl, M. Temmer, N. P. Savani, G. Collinson, A. Taktakishvili, P. J. MacNeice , and Y. Zheng, Propagation of the 2014 January 7 CME and Resulting Geomagnetic Non-Event, Astrophys. J, 812, 145, 2015

06/21/2015 15:30:00 UTC

2017-01-20T22:15:51Z

Davidwebb: /* References */

03/17/2015 04:00:00 UTC

2017-01-20T22:13:32Z

Davidwebb: /* References */

07/14/2012 17:00:00 UTC

2017-01-20T22:10:44Z

Davidwebb: /* References */

10/08/2012 05:00:00 UTC

2017-01-20T20:28:38Z

Davidwebb: /* References */

10/08/2012 05:00:00 UTC

2017-01-20T20:27:50Z

Davidwebb: /* References */

=Comment Section=
*This is a varSITI campaign event
*A good ICME, strong CME source, however, "stealth" surface signature (J. Zhang)
**A good example of "stealth" CME: bright CME, but no or very weak surface signature (in terms of no flare, dimming, filament eruption etc)
*This event has a very difficult to distinguish source region, if you look very closely at S22 W38 just before 00:00 UT on the 10/05 it is possible to see a very small disturbance on the Sun, especially in 304 Angstroms. (Hess)
* M. Temmer: clear on-disk signatures - movie from SDO - are visible. It is a "silent" CME, hard to catch for space weather forecasters, but not a "stealth" in sense of no solar surface signatures at all.
http://sdowww.lmsal.com/sdomedia/SunInTime/2012/10/04/daily_211-193-171.mov [October 4, 15UT, central south]

I put some images showing clear coronal restructuring and some discussion points under> http://www.uni-graz.at/~temmerma/download/varsiti/
*C. Moestl: looking at the whole October 4 SDO movie, there are also two other minor eruptions which I find very hard to distinguish from the 15 UT one (1. 7 UT, slightly west of disk center; 2. 0930 UT, south-east quadrant)
* timing - evolution from SDO FoV to coronagraph - is an issue and needs to be looked at in detail
* these eruptions are also visible in the SWAP data (http://proba2.oma.be/), including another minor one at 14h UT in the south-east quadrant (A. Devos)
*Discussion in USTC-China ISEST Workshop on April 19, 2014
**Inferred from GCS model based on STEREO/A, STEREO/B and SOHO coronagraphs, longitude W11 deg, latitude S20 degree
**Around this position, there was a minor activity from 14 to 15 UT on Oct. 14 seen in SDO AIA 193 images. The activity appeared as a weak dimming followed by a diffuse brightening.
**In EUVI-A 195, from 22 UT on Oct. 14, there was a very faint eruption above the south-east limb. This beyond-limb faint eruption is consistent with the heliospheric position of W11S20.
**The CME continued to accelerate to about 10 Rs with a peak speed of 800 km/s at 06 UT, Oct. 15.
**If the eruption started at 14 UT, Oct. 14, it took a long time (10 hrs) for the eruption to reach the COR1 FOV. It indicates that the eruption has a long-lasting low-speed low-acceleration phase

At Earth it produced a small storm, Dst=-105. Electron acceleration in the radiation belt has been measured by the Van Allen Probes and studied by Reeves, et al (2013), Thorne et al. (2013, and Kurita et al. (2016). studied by Reeves, G.D. et al (2013). [Added by D. Webb]

=Image Data=
==In-Situ Data==
A combination of SWEPAM and MAG data from the ACE Satellite: 
[[File:plot_sw_mag_plasma_2012100700.png|350px]]
[[File:plot_sw_mag_2012100700.png|400px]]
[[File:plot_sw_vel_2012100700.png|350px]] 
The blue lines are an approximation of the CME cloud and the red line denotes the shock.

==Jmaps==
Jmaps from STEREO A and B along the CME leading edge position angle 

[[File:jmapA20101005.jpg|500px]]
[[File:jmapB20101005.jpg|500px]]

 

==Heliospheric Imager Data==
[[File:20121008stereoa.gif]]
[[File:20121008stereob.gif]]

=Video Data=
[http://solar.gmu.edu/wiki/upload/phess4/20121008aia171.mp4 AIA 171] 
[http://solar.gmu.edu/wiki/upload/phess4/20121008aia193.mp4 AIA 193] 
[http://solar.gmu.edu/wiki/upload/phess4/20121008aia304.mp4 AIA 304] 
[http://solar.gmu.edu/wiki/upload/phess4/aia3041005.avi AIA 304 Running Difference Movie] 
[http://solar.gmu.edu/wiki/upload/phess4/aia1931005.avi AIA 195 Running Difference Movie] 
[http://solar.gmu.edu/wiki/upload/phess4/euvi1005.avi STEREO EUVIA 304] 
[http://solar.gmu.edu/wiki/upload/phess4/cor2A1005_good.avi STEREO COR2A] 
[http://solar.gmu.edu/wiki/upload/phess4/cor2B1005_good.avi STEREO COR2B] 
[http://solar.gmu.edu/wiki/upload/phess4/hi1A1005.avi STEREO HI1A] 
[http://solar.gmu.edu/wiki/upload/phess4/hi1b1005.avi STEREO HI1B] 
[http://solar.gmu.edu/wiki/upload/phess4/hi2A1005.avi STEREO HI2A] 
[http://solar.gmu.edu/wiki/upload/phess4/hi2b1005.avi STEREO HI2B] 
[http://solar.gmu.edu/wiki/upload/Adevos/20121004_swap_movie.mp4 PROBA2 SWAP 174] 
[http://solar.gmu.edu/wiki/upload/Adevos/20121004_swap_diff.mp4 PROBA2 SWAP 174 Difference Movie] 

=References=
- Reeves, G. D., et al. (2013), Electron acceleration in the heart of the Van Allen radiation belts, Science, 341(6149), 991–994, doi:10.1126/science.1237743.
- Thorne, R. M., et al. (2013), Rapid acceleration of relativistic radiation belt electrons by magnetospheric chorus, Nature, 504, 411–414, doi:10.1038/nature12889.
- Kurita, S., Y. Miyoshi, J. B. Blake, G. D. Reeves, and C. A. Kletzing (2016), Relativistic electron microbursts and variations in trapped MeV electron fluxes during the 8–9 October 2012 storm: SAMPEX and Van Allen Probes observations, Geophys. Res. Lett., 43, 3017–3025, doi:10.1002/2016GL068260.

10/08/2012 05:00:00 UTC

2017-01-20T20:27:08Z

Davidwebb: /* Comment Section */

Working Group 4

2016-05-25T21:04:17Z

Davidwebb: /* Updated WG4 Events as of May 2016 */

Campaign Event Group led by Dave Webb (USA), Nariaki Nitta (USA) and Luciano Rodriguez (Belgium).

A brief summary of the activity of WG4 at the workshop can be found [http://solar.gmu.edu/wiki/presentations/WG4_Summary_20130620.pdf here]. 

==Objectives==

*Provide textbook-style standard CME-ICME chain events from the Sun to the Earth based on the state-of-the-art observations and successful theoretical analysis and numerical simulation: happy stories

*Examine controversial Earth-Affecting CME/ICME pairs during the STEREO era (from 2007): surprising stories

*To analyse the complications that arise when linking CMEs to ICMEs

*To obtain new insights that could be applied when forecasting ICME arrivals at the Earth

*Integrate theory, simulations and observations in order to get a complete view of the chain of events from the Sun to the Earth

==Scientific Questions, Technique Approach/Methodology==

===What are the common issues when linking ICMEs to CMEs?===

*Multiple events

*Stealth CMEs

*CME deflection

*etc.

===Calculating arrival times===

*Projected vs 3D speeds

*Propagation models (DBM, ENLIL, etc.)

*Error margins

===When/why will a full halo CME not arrive to the Earth?===

===When/why will a narrow CME (as seen from L1) arrive to the Earth?===

===What solar parameters can we use to provide an estimation of geoeffectivity?===

===More interesting topics:===
*Forbush decreases (Mateja, Dragan, Darije)
*Sympathetic flares (Nariaki)
*SEPs (Bernd?)
*Prominence material in ICMEs, signatures in compositional data (Luciano)
*Determination of S/C path through the ICME, central or flank crossings
*Use of remote data to infer Bz: magnetograms, extrapolations, flux rope orientation
*False alarms: CMEs that did not arrive to the Earth when they were expected to, and viceversa.

===Working list and details of events===

==Updated WG4 Events as of May 2016 [D. Webb]==
URL: http://solar.gmu.edu/wiki/upload/phess4/VarSITI%20ISEST-MM%20WG4%20Campaign%20Events.docx

==As of September 2015 [D. Webb]==

• VarSITI-wide campaign study events:

1. 2012 July 12-14 CME. This event is selected by ISEST.

This is a textbook (TB) style event, with a clear chain of activity signatures all the way from the solar surface, inner corona and outer corona (X1.4 flare and fast CME), to in-situ near the Earth (a shock and magnetic cloud [MC]). Also of interest are the 2012 July 23-24 and other events from the same active region.

It produced an intense geomagnetic storm, Dst = -127nT. In a prior ISEST workshop, we agreed to study this event extensively.

URL: http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC

References: Dudik, J. et al., ApJ, 2014; Cheng, X. et al., ApJ, 2014; Moestl, C. et al., ApJ, 787, 119, 2014; Hess, P. & Zhang, J., ApJ, 792, 49, 2014 [http://adsabs.harvard.edu/abs/2014ApJ...792...49H Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times]; Shen, F. et al., JGR, 119, 7128, 2014;

2. 2012 October 4-8 CME. This event has been recommended by ISEST and SPeCIMEN.

This is an excellent stealth CME, i.e., a strong CME in the inner corona and ICME, but the solar disk signatures are multiple and weak, and it had slow propagation to Earth. At Earth a smaller storm, Dst=-105. Electron acceleration in the radiation belt has been studied by Reeves, G.D. et al (2013). (P)roblem event.

URL: http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC
References:

3. 2013 March 15-17 CME. Recommended by ISEST and SPeCIMEN.

At the Sun an M1.1 flare, erupting filament, type IV radio burst, fast halo CME. At Earth a shock, possible MC, SEP, and strong storm, Dst=-132. TB case. Modeled by C-C Wu.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2013_05:30:00_UTC
Refs:

4. 2013 June 1 CME. Recommended by ISEST and ROSMIC.

Possibly due to a slow CME on May 27 Coronal hole influence? Cause of big storm unclear, Dst=-119. P.

URL: http://solar.gmu.edu/heliophysics/index.php/05/31/2013_15:30:00_UTC
Refs:

5. 2015 March 15-17 CME. This event is selected by ISEST.

First “super” storm of SC24 was caused by an Earth-directed CME that erupted on 15 March 2015 from near disk center (S18W39) with a speed of 1120 km/s in the sky plane. N. Gopalswamy – this can be converted to an earthward speed of ~1025 km/s based on the source location on the Sun. The CME arrived with a MC on March 17 at 13:38 UT with a large southward field in the sheath (-15 nT) and in the front of the cloud (-25 nT). There were Dst dips corresponding to the sheath and cloud portions, with the deepest minimum Dst of 223 nT occurring at 23:00 UT on March 17. The speed of the MC was ~600 km/s, considerably smaller than the white-light CME speed of 1025 km/s.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2015_04:00:00_UTC

Refs: Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.; Wu et al., abs. for the SCOSTEP-WDS Workshop at NICT, Japan, Sept, 2015; Jackson, priv. comm.; Kamide, Y & K. Kusano, Space Weather, 13, 2015; Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1; Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015; P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf.

6. 2015 June 22-24 CME. This event is selected by ISEST.

Second “super” storm of SC24, and this year, was caused by an Earth-directed CME that erupted on 22 June 2015 from near disk center () with a speed of km/s in the sky plane. Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst =195.

N. Lugaz: The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME... The larger dip on the 23rd is due to the following CME... There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

N. Nitta: There were at least four eruptions during 18-22 June and the third one (associated with a M2 flare on 21 June) was a quite impressively circular CME, which I think contributed the most to the geo-space effects (the CME arrived much earlier than I had thought). Three CMEs seemed to have arrived without merging,.. The M6.5 flare on 22 June was not associated with a very geo-effective CME even though it arrived fast.

Y. Liu: This is actually a multi-step geomagnetic storm… The first dip was produced by the fluctuating southward field components upstream of the third shock, the second one by the southward field components downstream of the third shock, and the major one by the southward field components within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious geo-effectiveness... The fourth shock in the plot was associated with the June 22 M6.5 eruption, and it was beginning to overtake the ICME from behind at 1 AU. Another eruption on June 25 (M7.9) also produced a shock that impacted Earth.., but wasn’t geo-effective either.

E. Kilpua: The strongest Bs intervals and the Dst minimum in the June event are … preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have led to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

URL: http://solar.gmu.edu/heliophysics/index.php/06/21/2015_15:30:00_UTC

Refs.: Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

• Other ISEST WG4 events being studied:

7. 2012 March 7-9.

An X5 flare, wave, fast CME. At Earth a shock, magnetic cloud (MC), and strong storm, Dst=-131. TB case. Of interest because of the influence of a CH on a relatively modest CME.

8. 2012 July 23-24

This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

URL: http://solar.gmu.edu/heliophysics/index.php/07/23/2012_23:00:00_UTC
Refs: Russell, C. et al., ApJ, 770, 38, 2013; Ngwira, C. et al., GRL, 2013; Baker, D., Space Weather, 11, 585, 2013; Liu, D.L. et al., NComm., 5, 4381, 2014; Gopalswamy et al., E,P&S, 66, 104, 2014; Temmer and Nitta, Solar Phys., 290, 919, 2015;

9. 2014 January 6, 07:30, WL: Produced a GLE (see next).

- N. Gopalswamy reports that the January 6 and 7 CMEs are quite intriguing. The Jan. 6 event produced a GLE even though it had a speed <2000 km/s and originated behind the west limb (Thakur et al. 2014).

URL:
Refs: Thakur et al., ApJL, 2014

10. 2014 January 7-9

A “problem” event being studied for a Fall 2014 AGU session: SH51E: Challenges to Space Weather Forecasting and Data-Driven Modeling of the Sun Focused on January 2014; 19 Dec. 2014 (e.g., Webb, 2014).

The Jan. 7 CME was assoc. with a X1.2 flare near disk center (S12W08) and was ultrafast (~2400 km/s), but was likely deflected to the south and west so it was not geoefffective. It was a large SEP event, but not a GLE. The shock and sheath were likely detected at Earth (9, 19:40 UT) and Mars (10, 22:30 UT) – Moestl et al. (2015).

URL: http://solar.gmu.edu/heliophysics/index.php/01/08/2014-01/09/2014;
https://agu.confex.com/agu/fm14/meetingapp.cgi#Session/4428

Ref: Webb, An Overview of the 7 January 2014 X-Class Flare-CME and Space Weather Predictions, AGU SH51E-01, 2014; Moestl et al., Nat. Commun., 6, 7135, 2015; Gopalswamy et al., E,P&S, 66, 104, 2014;

11. 2014 September 10-13

An X1.6 flare and wave near Sun Center and a nearly symmetric halo CME. The evolution of the source active region (AR 12158) is also of interest.

The ICME at L1 on 12-13 Sept. mostly had strong northward field in the putative flux rope (several models produced). The southward fields, which drove the early storm activity, were in the sheaths trailing two IP shocks, the second one being the strongest. The ICME north field rapidly shut down the auroral and storm activity.

A STEREO SWx Group event. “U” case? B. Jackson runs a real time forecast site, and have included the Rosetta comet mission in the forecasts, currently using IPS data. A density response at Rosetta due to the Sept. 10 event was predicted for IPS and modeled using the ENLIL 3D-MHD code. We are looking for Rosetta solar wind data to confirm an ICME there.

URL: http://solar.gmu.edu/heliophysics/index.php/09/12/2014_15:26:00_UTC

Refs.: McKenna-Lawlor et al. EM&P, subm, 2015; B. Jackson, priv. comm.;

__________________

*MiniMAx24 list (https://igam07ws.uni-graz.at/mediawiki/index.php?title=Main_Page:Event_Studies)

*WG1 events

==Selected campaign events==

*Textbook example: [http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC 12 July 2012]

*Problematic event: [http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC 5 October 2012] (stealth CME, ICME trailed by a HSS)

*Backup problematic event: June 7 2013 (MC a bit weak)

==Future Plan==
* Collect results of simulations and models
* Compare and integrate simulations results with observations
* Start/continue the work related to the scientific questions

Working Group 4

2016-05-25T21:02:32Z

Davidwebb: /* Working list and details of events */

Campaign Event Group led by Dave Webb (USA), Nariaki Nitta (USA) and Luciano Rodriguez (Belgium).

A brief summary of the activity of WG4 at the workshop can be found [http://solar.gmu.edu/wiki/presentations/WG4_Summary_20130620.pdf here]. 

==Objectives==

*Provide textbook-style standard CME-ICME chain events from the Sun to the Earth based on the state-of-the-art observations and successful theoretical analysis and numerical simulation: happy stories

*Examine controversial Earth-Affecting CME/ICME pairs during the STEREO era (from 2007): surprising stories

*To analyse the complications that arise when linking CMEs to ICMEs

*To obtain new insights that could be applied when forecasting ICME arrivals at the Earth

*Integrate theory, simulations and observations in order to get a complete view of the chain of events from the Sun to the Earth

==Scientific Questions, Technique Approach/Methodology==

===What are the common issues when linking ICMEs to CMEs?===

*Multiple events

*Stealth CMEs

*CME deflection

*etc.

===Calculating arrival times===

*Projected vs 3D speeds

*Propagation models (DBM, ENLIL, etc.)

*Error margins

===When/why will a full halo CME not arrive to the Earth?===

===When/why will a narrow CME (as seen from L1) arrive to the Earth?===

===What solar parameters can we use to provide an estimation of geoeffectivity?===

===More interesting topics:===
*Forbush decreases (Mateja, Dragan, Darije)
*Sympathetic flares (Nariaki)
*SEPs (Bernd?)
*Prominence material in ICMEs, signatures in compositional data (Luciano)
*Determination of S/C path through the ICME, central or flank crossings
*Use of remote data to infer Bz: magnetograms, extrapolations, flux rope orientation
*False alarms: CMEs that did not arrive to the Earth when they were expected to, and viceversa.

===Working list and details of events===

==Updated WG4 Events as of May 2016==

==As of September 2015 [D. Webb]==

• VarSITI-wide campaign study events:

1. 2012 July 12-14 CME. This event is selected by ISEST.

This is a textbook (TB) style event, with a clear chain of activity signatures all the way from the solar surface, inner corona and outer corona (X1.4 flare and fast CME), to in-situ near the Earth (a shock and magnetic cloud [MC]). Also of interest are the 2012 July 23-24 and other events from the same active region.

It produced an intense geomagnetic storm, Dst = -127nT. In a prior ISEST workshop, we agreed to study this event extensively.

URL: http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC

References: Dudik, J. et al., ApJ, 2014; Cheng, X. et al., ApJ, 2014; Moestl, C. et al., ApJ, 787, 119, 2014; Hess, P. & Zhang, J., ApJ, 792, 49, 2014 [http://adsabs.harvard.edu/abs/2014ApJ...792...49H Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times]; Shen, F. et al., JGR, 119, 7128, 2014;

2. 2012 October 4-8 CME. This event has been recommended by ISEST and SPeCIMEN.

This is an excellent stealth CME, i.e., a strong CME in the inner corona and ICME, but the solar disk signatures are multiple and weak, and it had slow propagation to Earth. At Earth a smaller storm, Dst=-105. Electron acceleration in the radiation belt has been studied by Reeves, G.D. et al (2013). (P)roblem event.

URL: http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC
References:

3. 2013 March 15-17 CME. Recommended by ISEST and SPeCIMEN.

At the Sun an M1.1 flare, erupting filament, type IV radio burst, fast halo CME. At Earth a shock, possible MC, SEP, and strong storm, Dst=-132. TB case. Modeled by C-C Wu.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2013_05:30:00_UTC
Refs:

4. 2013 June 1 CME. Recommended by ISEST and ROSMIC.

Possibly due to a slow CME on May 27 Coronal hole influence? Cause of big storm unclear, Dst=-119. P.

URL: http://solar.gmu.edu/heliophysics/index.php/05/31/2013_15:30:00_UTC
Refs:

5. 2015 March 15-17 CME. This event is selected by ISEST.

First “super” storm of SC24 was caused by an Earth-directed CME that erupted on 15 March 2015 from near disk center (S18W39) with a speed of 1120 km/s in the sky plane. N. Gopalswamy – this can be converted to an earthward speed of ~1025 km/s based on the source location on the Sun. The CME arrived with a MC on March 17 at 13:38 UT with a large southward field in the sheath (-15 nT) and in the front of the cloud (-25 nT). There were Dst dips corresponding to the sheath and cloud portions, with the deepest minimum Dst of 223 nT occurring at 23:00 UT on March 17. The speed of the MC was ~600 km/s, considerably smaller than the white-light CME speed of 1025 km/s.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2015_04:00:00_UTC

Refs: Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.; Wu et al., abs. for the SCOSTEP-WDS Workshop at NICT, Japan, Sept, 2015; Jackson, priv. comm.; Kamide, Y & K. Kusano, Space Weather, 13, 2015; Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1; Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015; P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf.

6. 2015 June 22-24 CME. This event is selected by ISEST.

Second “super” storm of SC24, and this year, was caused by an Earth-directed CME that erupted on 22 June 2015 from near disk center () with a speed of km/s in the sky plane. Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst =195.

N. Lugaz: The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME... The larger dip on the 23rd is due to the following CME... There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

N. Nitta: There were at least four eruptions during 18-22 June and the third one (associated with a M2 flare on 21 June) was a quite impressively circular CME, which I think contributed the most to the geo-space effects (the CME arrived much earlier than I had thought). Three CMEs seemed to have arrived without merging,.. The M6.5 flare on 22 June was not associated with a very geo-effective CME even though it arrived fast.

Y. Liu: This is actually a multi-step geomagnetic storm… The first dip was produced by the fluctuating southward field components upstream of the third shock, the second one by the southward field components downstream of the third shock, and the major one by the southward field components within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious geo-effectiveness... The fourth shock in the plot was associated with the June 22 M6.5 eruption, and it was beginning to overtake the ICME from behind at 1 AU. Another eruption on June 25 (M7.9) also produced a shock that impacted Earth.., but wasn’t geo-effective either.

E. Kilpua: The strongest Bs intervals and the Dst minimum in the June event are … preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have led to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

URL: http://solar.gmu.edu/heliophysics/index.php/06/21/2015_15:30:00_UTC

Refs.: Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

• Other ISEST WG4 events being studied:

7. 2012 March 7-9.

An X5 flare, wave, fast CME. At Earth a shock, magnetic cloud (MC), and strong storm, Dst=-131. TB case. Of interest because of the influence of a CH on a relatively modest CME.

8. 2012 July 23-24

This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

URL: http://solar.gmu.edu/heliophysics/index.php/07/23/2012_23:00:00_UTC
Refs: Russell, C. et al., ApJ, 770, 38, 2013; Ngwira, C. et al., GRL, 2013; Baker, D., Space Weather, 11, 585, 2013; Liu, D.L. et al., NComm., 5, 4381, 2014; Gopalswamy et al., E,P&S, 66, 104, 2014; Temmer and Nitta, Solar Phys., 290, 919, 2015;

9. 2014 January 6, 07:30, WL: Produced a GLE (see next).

- N. Gopalswamy reports that the January 6 and 7 CMEs are quite intriguing. The Jan. 6 event produced a GLE even though it had a speed <2000 km/s and originated behind the west limb (Thakur et al. 2014).

URL:
Refs: Thakur et al., ApJL, 2014

10. 2014 January 7-9

A “problem” event being studied for a Fall 2014 AGU session: SH51E: Challenges to Space Weather Forecasting and Data-Driven Modeling of the Sun Focused on January 2014; 19 Dec. 2014 (e.g., Webb, 2014).

The Jan. 7 CME was assoc. with a X1.2 flare near disk center (S12W08) and was ultrafast (~2400 km/s), but was likely deflected to the south and west so it was not geoefffective. It was a large SEP event, but not a GLE. The shock and sheath were likely detected at Earth (9, 19:40 UT) and Mars (10, 22:30 UT) – Moestl et al. (2015).

URL: http://solar.gmu.edu/heliophysics/index.php/01/08/2014-01/09/2014;
https://agu.confex.com/agu/fm14/meetingapp.cgi#Session/4428

Ref: Webb, An Overview of the 7 January 2014 X-Class Flare-CME and Space Weather Predictions, AGU SH51E-01, 2014; Moestl et al., Nat. Commun., 6, 7135, 2015; Gopalswamy et al., E,P&S, 66, 104, 2014;

11. 2014 September 10-13

An X1.6 flare and wave near Sun Center and a nearly symmetric halo CME. The evolution of the source active region (AR 12158) is also of interest.

The ICME at L1 on 12-13 Sept. mostly had strong northward field in the putative flux rope (several models produced). The southward fields, which drove the early storm activity, were in the sheaths trailing two IP shocks, the second one being the strongest. The ICME north field rapidly shut down the auroral and storm activity.

A STEREO SWx Group event. “U” case? B. Jackson runs a real time forecast site, and have included the Rosetta comet mission in the forecasts, currently using IPS data. A density response at Rosetta due to the Sept. 10 event was predicted for IPS and modeled using the ENLIL 3D-MHD code. We are looking for Rosetta solar wind data to confirm an ICME there.

URL: http://solar.gmu.edu/heliophysics/index.php/09/12/2014_15:26:00_UTC

Refs.: McKenna-Lawlor et al. EM&P, subm, 2015; B. Jackson, priv. comm.;

__________________

*MiniMAx24 list (https://igam07ws.uni-graz.at/mediawiki/index.php?title=Main_Page:Event_Studies)

*WG1 events

==Selected campaign events==

*Textbook example: [http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC 12 July 2012]

*Problematic event: [http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC 5 October 2012] (stealth CME, ICME trailed by a HSS)

*Backup problematic event: June 7 2013 (MC a bit weak)

==Future Plan==
* Collect results of simulations and models
* Compare and integrate simulations results with observations
* Start/continue the work related to the scientific questions

Working Group 4

2015-09-09T20:05:14Z

Davidwebb: /* Working list and details of events */

Campaign Event Group led by Dave Webb (USA), Nariaki Nitta (USA) and Luciano Rodriguez (Belgium).

A brief summary of the activity of WG4 at the workshop can be found [http://solar.gmu.edu/wiki/presentations/WG4_Summary_20130620.pdf here]. 

==Objectives==

*Provide textbook-style standard CME-ICME chain events from the Sun to the Earth based on the state-of-the-art observations and successful theoretical analysis and numerical simulation: happy stories

*Examine controversial Earth-Affecting CME/ICME pairs during the STEREO era (from 2007): surprising stories

*To analyse the complications that arise when linking CMEs to ICMEs

*To obtain new insights that could be applied when forecasting ICME arrivals at the Earth

*Integrate theory, simulations and observations in order to get a complete view of the chain of events from the Sun to the Earth

==Scientific Questions, Technique Approach/Methodology==

===What are the common issues when linking ICMEs to CMEs?===

*Multiple events

*Stealth CMEs

*CME deflection

*etc.

===Calculating arrival times===

*Projected vs 3D speeds

*Propagation models (DBM, ENLIL, etc.)

*Error margins

===When/why will a full halo CME not arrive to the Earth?===

===When/why will a narrow CME (as seen from L1) arrive to the Earth?===

===What solar parameters can we use to provide an estimation of geoeffectivity?===

===More interesting topics:===
*Forbush decreases (Mateja, Dragan, Darije)
*Sympathetic flares (Nariaki)
*SEPs (Bernd?)
*Prominence material in ICMEs, signatures in compositional data (Luciano)
*Determination of S/C path through the ICME, central or flank crossings
*Use of remote data to infer Bz: magnetograms, extrapolations, flux rope orientation
*False alarms: CMEs that did not arrive to the Earth when they were expected to, and viceversa.

==Working list and details of events==

As of September 2015 [D. Webb]

• VarSITI-wide campaign study events:

1. 2012 July 12-14 CME. This event is selected by ISEST.

This is a textbook (TB) style event, with a clear chain of activity signatures all the way from the solar surface, inner corona and outer corona (X1.4 flare and fast CME), to in-situ near the Earth (a shock and magnetic cloud [MC]). Also of interest are the 2012 July 23-24 and other events from the same active region.

It produced an intense geomagnetic storm, Dst = -127nT. In a prior ISEST workshop, we agreed to study this event extensively.

URL: http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC

References: Dudik, J. et al., ApJ, 2014; Cheng, X. et al., ApJ, 2014; Moestl, C. et al., ApJ, 787, 119, 2014; Hess, P. & Zhang, J., ApJ, 792, 49, 2014 [http://adsabs.harvard.edu/abs/2014ApJ...792...49H Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times]; Shen, F. et al., JGR, 119, 7128, 2014;

2. 2012 October 4-8 CME. This event has been recommended by ISEST and SPeCIMEN.

This is an excellent stealth CME, i.e., a strong CME in the inner corona and ICME, but the solar disk signatures are multiple and weak, and it had slow propagation to Earth. At Earth a smaller storm, Dst=-105. Electron acceleration in the radiation belt has been studied by Reeves, G.D. et al (2013). (P)roblem event.

URL: http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC
References:

3. 2013 March 15-17 CME. Recommended by ISEST and SPeCIMEN.

At the Sun an M1.1 flare, erupting filament, type IV radio burst, fast halo CME. At Earth a shock, possible MC, SEP, and strong storm, Dst=-132. TB case. Modeled by C-C Wu.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2013_05:30:00_UTC
Refs:

4. 2013 June 1 CME. Recommended by ISEST and ROSMIC.

Possibly due to a slow CME on May 27 Coronal hole influence? Cause of big storm unclear, Dst=-119. P.

URL: http://solar.gmu.edu/heliophysics/index.php/05/31/2013_15:30:00_UTC
Refs:

5. 2015 March 15-17 CME. This event is selected by ISEST.

First “super” storm of SC24 was caused by an Earth-directed CME that erupted on 15 March 2015 from near disk center (S18W39) with a speed of 1120 km/s in the sky plane. N. Gopalswamy – this can be converted to an earthward speed of ~1025 km/s based on the source location on the Sun. The CME arrived with a MC on March 17 at 13:38 UT with a large southward field in the sheath (-15 nT) and in the front of the cloud (-25 nT). There were Dst dips corresponding to the sheath and cloud portions, with the deepest minimum Dst of 223 nT occurring at 23:00 UT on March 17. The speed of the MC was ~600 km/s, considerably smaller than the white-light CME speed of 1025 km/s.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2015_04:00:00_UTC

Refs: Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.; Wu et al., abs. for the SCOSTEP-WDS Workshop at NICT, Japan, Sept, 2015; Jackson, priv. comm.; Kamide, Y & K. Kusano, Space Weather, 13, 2015; Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1; Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015; P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf.

6. 2015 June 22-24 CME. This event is selected by ISEST.

Second “super” storm of SC24, and this year, was caused by an Earth-directed CME that erupted on 22 June 2015 from near disk center () with a speed of km/s in the sky plane. Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst =195.

N. Lugaz: The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME... The larger dip on the 23rd is due to the following CME... There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

N. Nitta: There were at least four eruptions during 18-22 June and the third one (associated with a M2 flare on 21 June) was a quite impressively circular CME, which I think contributed the most to the geo-space effects (the CME arrived much earlier than I had thought). Three CMEs seemed to have arrived without merging,.. The M6.5 flare on 22 June was not associated with a very geo-effective CME even though it arrived fast.

Y. Liu: This is actually a multi-step geomagnetic storm… The first dip was produced by the fluctuating southward field components upstream of the third shock, the second one by the southward field components downstream of the third shock, and the major one by the southward field components within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious geo-effectiveness... The fourth shock in the plot was associated with the June 22 M6.5 eruption, and it was beginning to overtake the ICME from behind at 1 AU. Another eruption on June 25 (M7.9) also produced a shock that impacted Earth.., but wasn’t geo-effective either.

E. Kilpua: The strongest Bs intervals and the Dst minimum in the June event are … preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have led to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

URL: http://solar.gmu.edu/heliophysics/index.php/06/21/2015_15:30:00_UTC

Refs.: Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

• Other ISEST WG4 events being studied:

7. 2012 March 7-9.

An X5 flare, wave, fast CME. At Earth a shock, magnetic cloud (MC), and strong storm, Dst=-131. TB case. Of interest because of the influence of a CH on a relatively modest CME.

8. 2012 July 23-24

This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

URL: http://solar.gmu.edu/heliophysics/index.php/07/23/2012_23:00:00_UTC
Refs: Russell, C. et al., ApJ, 770, 38, 2013; Ngwira, C. et al., GRL, 2013; Baker, D., Space Weather, 11, 585, 2013; Liu, D.L. et al., NComm., 5, 4381, 2014; Gopalswamy et al., E,P&S, 66, 104, 2014; Temmer and Nitta, Solar Phys., 290, 919, 2015;

9. 2014 January 6, 07:30, WL: Produced a GLE (see next).

- N. Gopalswamy reports that the January 6 and 7 CMEs are quite intriguing. The Jan. 6 event produced a GLE even though it had a speed <2000 km/s and originated behind the west limb (Thakur et al. 2014).

URL:
Refs: Thakur et al., ApJL, 2014

10. 2014 January 7-9

A “problem” event being studied for a Fall 2014 AGU session: SH51E: Challenges to Space Weather Forecasting and Data-Driven Modeling of the Sun Focused on January 2014; 19 Dec. 2014 (e.g., Webb, 2014).

The Jan. 7 CME was assoc. with a X1.2 flare near disk center (S12W08) and was ultrafast (~2400 km/s), but was likely deflected to the south and west so it was not geoefffective. It was a large SEP event, but not a GLE. The shock and sheath were likely detected at Earth (9, 19:40 UT) and Mars (10, 22:30 UT) – Moestl et al. (2015).

URL: http://solar.gmu.edu/heliophysics/index.php/01/08/2014-01/09/2014;
https://agu.confex.com/agu/fm14/meetingapp.cgi#Session/4428

Ref: Webb, An Overview of the 7 January 2014 X-Class Flare-CME and Space Weather Predictions, AGU SH51E-01, 2014; Moestl et al., Nat. Commun., 6, 7135, 2015; Gopalswamy et al., E,P&S, 66, 104, 2014;

11. 2014 September 10-13

An X1.6 flare and wave near Sun Center and a nearly symmetric halo CME. The evolution of the source active region (AR 12158) is also of interest.

The ICME at L1 on 12-13 Sept. mostly had strong northward field in the putative flux rope (several models produced). The southward fields, which drove the early storm activity, were in the sheaths trailing two IP shocks, the second one being the strongest. The ICME north field rapidly shut down the auroral and storm activity.

A STEREO SWx Group event. “U” case? B. Jackson runs a real time forecast site, and have included the Rosetta comet mission in the forecasts, currently using IPS data. A density response at Rosetta due to the Sept. 10 event was predicted for IPS and modeled using the ENLIL 3D-MHD code. We are looking for Rosetta solar wind data to confirm an ICME there.

URL: http://solar.gmu.edu/heliophysics/index.php/09/12/2014_15:26:00_UTC

Refs.: McKenna-Lawlor et al. EM&P, subm, 2015; B. Jackson, priv. comm.;

__________________

*MiniMAx24 list (https://igam07ws.uni-graz.at/mediawiki/index.php?title=Main_Page:Event_Studies)

*WG1 events

==Selected campaign events==

*Textbook example: [http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC 12 July 2012]

*Problematic event: [http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC 5 October 2012] (stealth CME, ICME trailed by a HSS)

*Backup problematic event: June 7 2013 (MC a bit weak)

==Future Plan==
* Collect results of simulations and models
* Compare and integrate simulations results with observations
* Start/continue the work related to the scientific questions

Working Group 4

2015-09-09T20:01:59Z

Davidwebb: /* Preliminary list of events */

Campaign Event Group led by Dave Webb (USA), Nariaki Nitta (USA) and Luciano Rodriguez (Belgium).

A brief summary of the activity of WG4 at the workshop can be found [http://solar.gmu.edu/wiki/presentations/WG4_Summary_20130620.pdf here]. 

==Objectives==

*Provide textbook-style standard CME-ICME chain events from the Sun to the Earth based on the state-of-the-art observations and successful theoretical analysis and numerical simulation: happy stories

*Examine controversial Earth-Affecting CME/ICME pairs during the STEREO era (from 2007): surprising stories

*To analyse the complications that arise when linking CMEs to ICMEs

*To obtain new insights that could be applied when forecasting ICME arrivals at the Earth

*Integrate theory, simulations and observations in order to get a complete view of the chain of events from the Sun to the Earth

==Scientific Questions, Technique Approach/Methodology==

===What are the common issues when linking ICMEs to CMEs?===

*Multiple events

*Stealth CMEs

*CME deflection

*etc.

===Calculating arrival times===

*Projected vs 3D speeds

*Propagation models (DBM, ENLIL, etc.)

*Error margins

===When/why will a full halo CME not arrive to the Earth?===

===When/why will a narrow CME (as seen from L1) arrive to the Earth?===

===What solar parameters can we use to provide an estimation of geoeffectivity?===

===More interesting topics:===
*Forbush decreases (Mateja, Dragan, Darije)
*Sympathetic flares (Nariaki)
*SEPs (Bernd?)
*Prominence material in ICMEs, signatures in compositional data (Luciano)
*Determination of S/C path through the ICME, central or flank crossings
*Use of remote data to infer Bz: magnetograms, extrapolations, flux rope orientation
*False alarms: CMEs that did not arrive to the Earth when they were expected to, and viceversa.

==Working list and details of events==

As of September 2015 [D. Webb]

• VarSITI-wide campaign study events:

1. 2012 July 12-14 (NN; BS: DW; MT; KM; many) CME. This event is selected by ISEST.
This is a textbook (TB) style event, with a clear chain of activity signatures all the way from the solar surface, inner corona and outer corona (X1.4 flare and fast CME), to in-situ near the Earth (a shock and magnetic cloud [MC]). Also of interest are the 2012 July 23-24 and other events from the same active region.

It produced an intense geomagnetic storm, Dst = -127nT. In a prior ISEST workshop, we agreed to study this event extensively.

URL: http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC

References: Dudik, J. et al., ApJ, 2014; Cheng, X. et al., ApJ, 2014; Moestl, C. et al., ApJ, 787, 119, 2014; Hess, P. & Zhang, J., ApJ, 792, 49, 2014 [http://adsabs.harvard.edu/abs/2014ApJ...792...49H Stereoscopic Study of the Kinematic Evolution of a Coronal Mass Ejection and Its Driven Shock from the Sun to the Earth and the Prediction of Their Arrival Times]; Shen, F. et al., JGR, 119, 7128, 2014;

2. 2012 October 4-8 (DW; KM) CME. This event has been recommended by ISEST and SPeCIMEN.
This is an excellent stealth CME, i.e., a strong CME in the inner corona and ICME, but the solar disk signatures are multiple and weak, and it had slow propagation to Earth. At Earth a smaller storm, Dst=-105. Electron acceleration in the radiation belt has been studied by Reeves, G.D. et al (2013). (P)roblem event.

URL: http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC
References:

3. 2013 March 15-17 (MT; DW; KM: KS) CME. Recommended by ISEST and SPeCIMEN.
At the Sun an M1.1 flare, erupting filament, type IV radio burst, fast halo CME. At Earth a shock, possible MC, SEP, and strong storm, Dst=-132. TB case. Modeled by C-C Wu.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2013_05:30:00_UTC
Refs:

4. 2013 June 1 (NN; MT; KS; KM) CME. Recommended by ISEST and ROSMIC.
Possibly due to a slow CME on May 27 Coronal hole influence? Cause of big storm unclear, Dst=-119. P.

URL: http://solar.gmu.edu/heliophysics/index.php/05/31/2013_15:30:00_UTC
Refs:

5. 2015 March 15-17 (CW; BJ; NG) CME. This event is selected by ISEST.
First “super” storm of SC24 was caused by an Earth-directed CME that erupted on 15 March 2015 from near disk center (S18W39) with a speed of 1120 km/s in the sky plane. N. Gopalswamy – this can be converted to an earthward speed of ~1025 km/s based on the source location on the Sun. The CME arrived with a MC on March 17 at 13:38 UT with a large southward field in the sheath (-15 nT) and in the front of the cloud (-25 nT). There were Dst dips corresponding to the sheath and cloud portions, with the deepest minimum Dst of 223 nT occurring at 23:00 UT on March 17. The speed of the MC was ~600 km/s, considerably smaller than the white-light CME speed of 1025 km/s.

URL: http://solar.gmu.edu/heliophysics/index.php/03/17/2015_04:00:00_UTC

Refs: Gopalswamy et al., Proc. 14th International Ionospheric Effects Symposium, May 12-14, 2015, Alexandria, VA.; Wu et al., abs. for the SCOSTEP-WDS Workshop at NICT, Japan, Sept, 2015; Jackson, priv. comm.; Kamide, Y & K. Kusano, Space Weather, 13, 2015; Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1; Kataoka, R., D. Shiota, E. Kilpua, K. Keika, JGR-A, accepted, July 2015; P. Gallagher press release: http://files.mail-list.com/m/iswinewsletter/2015-07-space-weather-scans-solar-storms.pdf.

6. 2015 June 22-24 (Many) CME. This event is selected by ISEST.
Second “super” storm of SC24, and this year, was caused by an Earth-directed CME that erupted on 22 June 2015 from near disk center () with a speed of km/s in the sky plane. Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst =195.

N. Lugaz: The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME... The larger dip on the 23rd is due to the following CME... There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

N. Nitta: There were at least four eruptions during 18-22 June and the third one (associated with a M2 flare on 21 June) was a quite impressively circular CME, which I think contributed the most to the geo-space effects (the CME arrived much earlier than I had thought). Three CMEs seemed to have arrived without merging,.. The M6.5 flare on 22 June was not associated with a very geo-effective CME even though it arrived fast.

Y. Liu: This is actually a multi-step geomagnetic storm… The first dip was produced by the fluctuating southward field components upstream of the third shock, the second one by the southward field components downstream of the third shock, and the major one by the southward field components within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious geo-effectiveness... The fourth shock in the plot was associated with the June 22 M6.5 eruption, and it was beginning to overtake the ICME from behind at 1 AU. Another eruption on June 25 (M7.9) also produced a shock that impacted Earth.., but wasn’t geo-effective either.

E. Kilpua: The strongest Bs intervals and the Dst minimum in the June event are … preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have led to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

URL: http://solar.gmu.edu/heliophysics/index.php/06/21/2015_15:30:00_UTC

Refs.: Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

• Other ISEST WG4 events being studied:

7. 2012 March 7-9 (NN; KS). An X5 flare, wave, fast CME. At Earth a shock, magnetic cloud (MC), and strong storm, Dst=-131. TB case. Of interest because of the influence of a CH on a relatively modest CME.

8. 2012 July 23-24 (NN; MT; DW; NG)
This was the famous energetic, very fast event directed at STEREO-A. There were two consecutive prominence eruption/flares starting about 02:20 UT on July 23, seen best in SOHO and STEREO-B observations. The shock hit STEREO-A on July 23, 20:55 UT, followed by two ICMEs, the first starting about 23:00 UT and the second at 01:51 UT on July 24.

- N. Nitta says “It was not an Earth-affecting event, but it was said to have possibly been as geoeffective as the Carrington event had it occurred 9 days earlier [and been aimed at Earth-DW]. I think it is important to understand the interplanetary conditions as disturbed by AR 11520 over an extended period.”

- M. Temmer: “i am currently working together with Nariaki on the complex (two-step) eruption from July 23, 2012 event aiming to simulate the short arrival time and high impact speed by using the analytical drag-based-model. the low density in interplanetary space as well as the high mass of the CME might be the decisive factors for this event to be so fast. The question remains whether the event from July 19 is able to lower the density over several days and as such is able to change the interplanetary conditions. i had during the process of the analysis nice discussions with Ying Liu and Janet Luhmann. We would like to encourage people to take a closer look on this event. We had subjective interpretations of the white-light structures, but most important found no conclusion on the high magnetic field as measured in-situ for both magnetic structures. Is it maybe something intrinsic to the active region? … it would be good to get modelers involved for gaining some deeper insight into the complex eruption process and its in-situ effects.”

URL: http://solar.gmu.edu/heliophysics/index.php/07/23/2012_23:00:00_UTC
Refs: Russell, C. et al., ApJ, 770, 38, 2013; Ngwira, C. et al., GRL, 2013; Baker, D., Space Weather, 11, 585, 2013; Liu, D.L. et al., NComm., 5, 4381, 2014; Gopalswamy et al., E,P&S, 66, 104, 2014; Temmer and Nitta, Solar Phys., 290, 919, 2015;

9. 2014 January 6 (NN; NG), 07:30, WL: Produced a GLE (see next).
- N. Gopalswamy reports that the January 6 and 7 CMEs are quite intriguing. The Jan. 6 event produced a GLE even though it had a speed <2000 km/s and originated behind the west limb (Thakur et al. 2014).

URL:
Refs: Thakur et al., ApJL, 2014

10. 2014 January 7-9 (NN; NG; CM, DW)
A “problem” event being studied for a Fall 2014 AGU session: SH51E: Challenges to Space Weather Forecasting and Data-Driven Modeling of the Sun Focused on January 2014; 19 Dec. 2014 (e.g., Webb, 2014).

The Jan. 7 CME was assoc. with a X1.2 flare near disk center (S12W08) and was ultrafast (~2400 km/s), but was likely deflected to the south and west so it was not geoefffective. It was a large SEP event, but not a GLE. The shock and sheath were likely detected at Earth (9, 19:40 UT) and Mars (10, 22:30 UT) – Moestl et al. (2015).

URL: http://solar.gmu.edu/heliophysics/index.php/01/08/2014-01/09/2014;
https://agu.confex.com/agu/fm14/meetingapp.cgi#Session/4428

Ref: Webb, An Overview of the 7 January 2014 X-Class Flare-CME and Space Weather Predictions, AGU SH51E-01, 2014; Moestl et al., Nat. Commun., 6, 7135, 2015; Gopalswamy et al., E,P&S, 66, 104, 2014;

11. 2014 September 10-13 (NN; MT; DW; KM)
An X1.6 flare and wave near Sun Center and a nearly symmetric halo CME. The evolution of the source active region (AR 12158) is also of interest.

The ICME at L1 on 12-13 Sept. mostly had strong northward field in the putative flux rope (several models produced). The southward fields, which drove the early storm activity, were in the sheaths trailing two IP shocks, the second one being the strongest. The ICME north field rapidly shut down the auroral and storm activity.

A STEREO SWx Group event. “U” case? B. Jackson runs a real time forecast site, and have included the Rosetta comet mission in the forecasts, currently using IPS data. A density response at Rosetta due to the Sept. 10 event was predicted for IPS and modeled using the ENLIL 3D-MHD code. We are looking for Rosetta solar wind data to confirm an ICME there.

URL: http://solar.gmu.edu/heliophysics/index.php/09/12/2014_15:26:00_UTC

Refs.: McKenna-Lawlor et al. EM&P, subm, 2015; B. Jackson, priv. comm.;

__________________

*MiniMAx24 list (https://igam07ws.uni-graz.at/mediawiki/index.php?title=Main_Page:Event_Studies)

*WG1 events

==Selected campaign events==

*Textbook example: [http://solar.gmu.edu/heliophysics/index.php/07/14/2012_17:00:00_UTC 12 July 2012]

*Problematic event: [http://solar.gmu.edu/heliophysics/index.php/10/08/2012_05:00:00_UTC 5 October 2012] (stealth CME, ICME trailed by a HSS)

*Backup problematic event: June 7 2013 (MC a bit weak)

==Future Plan==
* Collect results of simulations and models
* Compare and integrate simulations results with observations
* Start/continue the work related to the scientific questions

01/08/2014-01/09/2014

2015-09-09T19:56:50Z

Davidwebb: /* References */

01/08/2014-01/09/2014

2015-09-09T19:55:45Z

Davidwebb: /* References */

09/12/2014 15:26:00 UTC

2015-09-09T19:52:29Z

Davidwebb: /* Heliospheric Data */

09/12/2014 15:26:00 UTC

2015-09-09T19:50:39Z

Davidwebb:

==Comments==

An X1.6 flare and wave near Sun Center and a nearly symmetric halo CME on Sept. 10. The ICME at L1 on 12-13 Sept., following two IP shocks, mostly had strong northward field in the putative flux rope (several models produced). The southward fields, which drove the early storm activity, were in the sheaths trailing two IP shocks, the second one being the strongest. The ICME north field rapidly shut down the auroral and storm activity.

A STEREO SWx Group event. B. Jackson at UCSD runs a real time forecast site, and have included the Rosetta comet mission in the forecasts, currently using IPS data. A density response at Rosetta due to the Sept. 10 event was predicted for IPS and modeled using the ENLIL 3D-MHD code. We are looking for Rosetta solar wind data to confirm an ICME there.

==Solar Data==

[[File:20140911_xray.gif|400px]]

*GOES X-ray plot showing the X1.6 peak level flare.

[[File:CORIMP 20140910.jpg|500px]]

*Tracking program on CME based on realtime data listed in the CORIMP "Weekly CME detections (past 7 days)" online here: 
http://alshamess.ifa.hawaii.edu/CORIMP 
[From Jason Bryne]

==Heliospheric Data==

*Link to GSFC SWRC Enlil prediction run on Sept. 10 at 11:58 pm. 
http://iswa.gsfc.nasa.gov/ENSEMBLE/2014-09-10_ncmes1_sims18_LIHUE079/20140910_181800_ncmes1_sims18_LIHUE079_anim_tim-den.gif

==In-Situ Data==

[[File:Mag_swe_7d_9sep2014.gif|400px]]

*ACE plasma and magnetic field plots are Sept. 9-15, 2014 showing two shocks at 11, 22:56 UT and 12, 15:26 UT. Southward field in the shock sheaths drives some storminess but Bz in the long duration ICME following the second shock is entirely northward, shutting down the storm activity.

[[File:wind_20140911-14.gif|500px]]

*Nitta's plot of ACE RTSW data in the style of K. Marubashi (http://www.lmsal.com/nitta/outgoing/nrt/plot_sw_mag_ace_rtsw_201409110900_201409142100.gif). The bottom panel suggests that the closest MC type is WNE (RH) in reference to Mulligan, Russell and Luhmann (1999) (http://www.lmsal.com/nitta/outgoing/nrt/mc_mulligan_20140912.png.) For this event people predicted either WSE or SEN with Bz<0, and LH. [Plot from Nariki Nitta on Sept. 15, 2014]

*THE "FORBUSH REBOUND": Radiation levels in the stratosphere are back to normal following a mid-September dip caused by one of the strongest solar storms in years. The story begins three weeks ago. On Sept. 12th a CME hit Earth head-on, sparking a G3-class geomagnetic storm. Using a helium balloon, the students of Earth to Sky Calculus launched a radiation sensor into the storm, expecting to measure an increase in energetic particles. Instead of more, however, they measured less. The CME had swept away many of the cosmic rays around Earth and so radiation levels in the stratosphere dropped.

The CME was long gone on Sept. 28th when they repeated the experiment and found radiation levels returning to pre-storm values.
The drop in radiation is called a "Forbush Decrease" after the 20th century physicist Scott Forbush who first described it. This would make the bounce-back a "Forbush Rebound." According to the data, the rebound took less than two weeks and possibly only a few days. The next time a CME hits, the students plan to launch balloons with a faster cadence to better measure the stratosphere's response time.
The group uses a Space Weather Buoy--an insulated capsule containing an X-ray/gamma-ray detector (10 keV - 20 MeV), multiple video cameras, GPS trackers, and other sensors. The payload went to 108,700 feet above the Death Valley National Park. 
From Spaceweather.com, issue 3 Oct. 2014.

==References==

- McKenna-Lawlor et al. EM&P, subm, 2015

07/14/2012 17:00:00 UTC

2015-09-09T19:44:51Z

Davidwebb: /* References */

03/17/2015 04:00:00 UTC

2015-09-09T19:39:43Z

Davidwebb: /* References */

06/21/2015 15:30:00 UTC

2015-09-09T19:32:47Z

Davidwebb: /* References */

=Comment Section=
*Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst near -200 (Hess) 

*WG4 EMAIL DISCUSSION ABOUT EVENT:

- July 14, 2015 
This event would perfectly fit as VarSITI Campaign Event. There are a lot of interesting aspects and the observations are quite nice to track the full chain of action and reaction when interacting with Earth (maybe also interesting for other VarSITI projects, e.g. ROSMIC?).
Cheers,
Manuela

This is a very interesting event indeed!

The discussion of multi-step storms reminds me of this 2002 paper. It has discussion on plasma sheet effect on ring current (and Dst) and in particular shows an interesting simulation results where two earlier Bs periods were removed and its effect to the total intensity of the storm studied. It seems that removing the earlier Bs peaks did not affect significantly to the total intensity of the storm.
http://onlinelibrary.wiley.com/doi/10.1029/2001JA000023/full

The strongest Bs intervals and the Dst minimum in the June event are indeed preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have lead to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

greetings,
Emilia

- July 13, 2015 
Hi Dave et al.,

Here is a plot combining Wind data and Dst. This is actually a multi-step
geomagnetic storm with the global minimum of -195 nT. The first dip was
produced by the fluctuating southward field components upstream of the
third shock, the second one by the southward field components downstream
of the third shock, and the major one by the southward field components
within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I
agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious
geo-effectiveness, as you can see from the data. The fourth shock in the
plot was associated with the June 22 M6.5 eruption, and it was beginning
to overtake the ICME from behind at 1 AU. Another eruption on June 25
(M7.9) also produced a shock that impacted Earth (not shown in the plot),
but it didn't produce geo-effectiveness either.

Also we see another 2 proceeding shocks as pointed out by Noe. These
multiple preceding shocks and sheaths may precondition the magnetosphere
for the growth of a strong geomagnetic storm (say, by feeding plasma to
the plasma sheet). I am not sure if the third shock was propagating into a
preceding ejecta, because I don't see clear ICME signatures upstream of
the shock. The fluctuating southward fields upstream of the third shock
may be produced by amplification of the ambient fields by the preceding
shocks.

Best,
Ying

On Mon, July 13, 2015 2:00 pm, Nariaki Nitta wrote:
> Dave,
>
> I normally look for shocks rather than ICMEs on ACE RTSW data. I don't
> think your M6.5 flare (on 22 June) had to do with the big Dst decrease
> during 22-23 June. The CME associated with the M6.5 flare was fast but
> not geo-effective (see
> https://twitter.com/halocme/status/613835532116828160). Different
> thoughts?
>
> Nariaki
>
> David Webb wrote on 13.07.15 13:48:
>
>> Nariaki,
>>
>> Of course I knew you would have it figured out! I guess we all need to
>> get on Twitter- wonder when NOAA will start sending out "official"
>> forecasts via Twitter!! Do I need to be a Twitter "subscriber" to get
>> your tweets?
>>
>> So I assume you ID the 3 CMEs as the shock arrival times. Again let's
>> be careful to differentiate shock from CME/ICME arrivals. Noe is saying
>> that one of the early shocks is propagating thru a preceding CME. And
>> what happened to the M6.5 event? What drove Dst to such low levels?
>>
>> Questions, questions,
>> Dave
>>
>> On Mon, Jul 13, 2015 at 4:29 PM, Nariaki Nitta <nitta@lmsal.com
>> <mailto:nitta@lmsal.com>> wrote:
>>
>> Dave,
>>
>> While you were preparing for SHINE, I tweeted a couple of time on
>> the road (therefore no detailed image analysis). There were at least four
>> eruptions during 18-22 June and the third one (associated with a M2
>> flare on 21 June) was a quite impressively circular CME
>> (https://twitter.com/halocme/status/612498918639677440), which I
>> think contributed the most to the geo-space effects (the CME arrived much
>> earlier than I had thought). Three CMEs seemed to arrive without
>> merging, see https://twitter.com/halocme/status/613216284675821568 (I
>> had to adjust the time axes of the plots). As of 23 June, it looked
>> possible that the Dst may hit -200 nT
>> (https://twitter.com/halocme/status/613227633074028544, indeed
>> auroras in California!). The M6.5 flare on 22 June was not associated
>> with a very geo-effective CME even though it arrived fast.
>>
>> The most recent storm (13 July) was much less impressive, even its
>> origin not being entirely clear.
>>
>> Nariaki
>>

Hi Dave et al.,

The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME, something I have been looking at recently. The larger dip on the 23rd is due to the following CME.
Wind data is attached. There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

Best,
Noé Lugaz

On Jul 13, 2015, at 3:26 PM, David Webb <david.webb@bc.edu> wrote:

Kyoto shows that this storm nearly reached "superstorm" (Dst<-200nT) level.
http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201506/dst1506.png

Many of us may have been distracted with our preparations for SHINE. Manuela first alerted us. Do we understand the cause-effect for it? Tamitha's recent video showed that it had significant geo-effects. There were apparently a series of flares/CMEs/EPs on June 21-22. Probably the storm was driven by the M7 event on June 22 but are we sure; was it a compound event?
-------

=Image Data=
[[File:20150623 satenv.gif]] 

[[File:Ace-mag-swepam-7-day.gif‎]] 

[[File:YL Wind ICMEs 21-25June2015.jpg|500px]] 

Courtesy Ying Liu.

=Video Data=

=References=

Liu, Y. at al., Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability, subm. ApJL, arXiv:1508.01267v1.

07/14/2012 17:00:00 UTC

2015-07-28T15:26:39Z

Davidwebb: /* References */

06/21/2015 15:30:00 UTC

2015-07-16T15:12:22Z

Davidwebb: /* Image Data */

06/21/2015 15:30:00 UTC

2015-07-15T21:51:57Z

Davidwebb: /* Image Data */

06/21/2015 15:30:00 UTC

2015-07-15T21:51:37Z

Davidwebb: /* Image Data */

=Comment Section=
*Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst near -200 (Hess) 

*WG4 EMAIL DISCUSSION ABOUT EVENT:

- July 14, 2015 
This event would perfectly fit as VarSITI Campaign Event. There are a lot of interesting aspects and the observations are quite nice to track the full chain of action and reaction when interacting with Earth (maybe also interesting for other VarSITI projects, e.g. ROSMIC?).
Cheers,
Manuela

This is a very interesting event indeed!

The discussion of multi-step storms reminds me of this 2002 paper. It has discussion on plasma sheet effect on ring current (and Dst) and in particular shows an interesting simulation results where two earlier Bs periods were removed and its effect to the total intensity of the storm studied. It seems that removing the earlier Bs peaks did not affect significantly to the total intensity of the storm.
http://onlinelibrary.wiley.com/doi/10.1029/2001JA000023/full

The strongest Bs intervals and the Dst minimum in the June event are indeed preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have lead to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

greetings,
Emilia

- July 13, 2015 
Hi Dave et al.,

Here is a plot combining Wind data and Dst. This is actually a multi-step
geomagnetic storm with the global minimum of -195 nT. The first dip was
produced by the fluctuating southward field components upstream of the
third shock, the second one by the southward field components downstream
of the third shock, and the major one by the southward field components
within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I
agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious
geo-effectiveness, as you can see from the data. The fourth shock in the
plot was associated with the June 22 M6.5 eruption, and it was beginning
to overtake the ICME from behind at 1 AU. Another eruption on June 25
(M7.9) also produced a shock that impacted Earth (not shown in the plot),
but it didn't produce geo-effectiveness either.

Also we see another 2 proceeding shocks as pointed out by Noe. These
multiple preceding shocks and sheaths may precondition the magnetosphere
for the growth of a strong geomagnetic storm (say, by feeding plasma to
the plasma sheet). I am not sure if the third shock was propagating into a
preceding ejecta, because I don't see clear ICME signatures upstream of
the shock. The fluctuating southward fields upstream of the third shock
may be produced by amplification of the ambient fields by the preceding
shocks.

Best,
Ying

On Mon, July 13, 2015 2:00 pm, Nariaki Nitta wrote:
> Dave,
>
> I normally look for shocks rather than ICMEs on ACE RTSW data. I don't
> think your M6.5 flare (on 22 June) had to do with the big Dst decrease
> during 22-23 June. The CME associated with the M6.5 flare was fast but
> not geo-effective (see
> https://twitter.com/halocme/status/613835532116828160). Different
> thoughts?
>
> Nariaki
>
> David Webb wrote on 13.07.15 13:48:
>
>> Nariaki,
>>
>> Of course I knew you would have it figured out! I guess we all need to
>> get on Twitter- wonder when NOAA will start sending out "official"
>> forecasts via Twitter!! Do I need to be a Twitter "subscriber" to get
>> your tweets?
>>
>> So I assume you ID the 3 CMEs as the shock arrival times. Again let's
>> be careful to differentiate shock from CME/ICME arrivals. Noe is saying
>> that one of the early shocks is propagating thru a preceding CME. And
>> what happened to the M6.5 event? What drove Dst to such low levels?
>>
>> Questions, questions,
>> Dave
>>
>> On Mon, Jul 13, 2015 at 4:29 PM, Nariaki Nitta <nitta@lmsal.com
>> <mailto:nitta@lmsal.com>> wrote:
>>
>> Dave,
>>
>> While you were preparing for SHINE, I tweeted a couple of time on
>> the road (therefore no detailed image analysis). There were at least four
>> eruptions during 18-22 June and the third one (associated with a M2
>> flare on 21 June) was a quite impressively circular CME
>> (https://twitter.com/halocme/status/612498918639677440), which I
>> think contributed the most to the geo-space effects (the CME arrived much
>> earlier than I had thought). Three CMEs seemed to arrive without
>> merging, see https://twitter.com/halocme/status/613216284675821568 (I
>> had to adjust the time axes of the plots). As of 23 June, it looked
>> possible that the Dst may hit -200 nT
>> (https://twitter.com/halocme/status/613227633074028544, indeed
>> auroras in California!). The M6.5 flare on 22 June was not associated
>> with a very geo-effective CME even though it arrived fast.
>>
>> The most recent storm (13 July) was much less impressive, even its
>> origin not being entirely clear.
>>
>> Nariaki
>>

Hi Dave et al.,

The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME, something I have been looking at recently. The larger dip on the 23rd is due to the following CME.
Wind data is attached. There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

Best,
Noé Lugaz

On Jul 13, 2015, at 3:26 PM, David Webb <david.webb@bc.edu> wrote:

Kyoto shows that this storm nearly reached "superstorm" (Dst<-200nT) level.
http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201506/dst1506.png

Many of us may have been distracted with our preparations for SHINE. Manuela first alerted us. Do we understand the cause-effect for it? Tamitha's recent video showed that it had significant geo-effects. There were apparently a series of flares/CMEs/EPs on June 21-22. Probably the storm was driven by the M7 event on June 22 but are we sure; was it a compound event?
-------

=Image Data=
[[File:20150623 satenv.gif]] 

[[File:Ace-mag-swepam-7-day.gif‎]] 

[[File:YL Wind ICMEs 21-25June2015.jpg|350px]] 

Courtesy Yuming Wang.

=Video Data=

=References=

06/21/2015 15:30:00 UTC

2015-07-15T21:48:53Z

Davidwebb: /* Image Data */

=Comment Section=
*Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst near -200 (Hess) 

*WG4 EMAIL DISCUSSION ABOUT EVENT:

- July 14, 2015 
This event would perfectly fit as VarSITI Campaign Event. There are a lot of interesting aspects and the observations are quite nice to track the full chain of action and reaction when interacting with Earth (maybe also interesting for other VarSITI projects, e.g. ROSMIC?).
Cheers,
Manuela

This is a very interesting event indeed!

The discussion of multi-step storms reminds me of this 2002 paper. It has discussion on plasma sheet effect on ring current (and Dst) and in particular shows an interesting simulation results where two earlier Bs periods were removed and its effect to the total intensity of the storm studied. It seems that removing the earlier Bs peaks did not affect significantly to the total intensity of the storm.
http://onlinelibrary.wiley.com/doi/10.1029/2001JA000023/full

The strongest Bs intervals and the Dst minimum in the June event are indeed preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have lead to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

greetings,
Emilia

- July 13, 2015 
Hi Dave et al.,

Here is a plot combining Wind data and Dst. This is actually a multi-step
geomagnetic storm with the global minimum of -195 nT. The first dip was
produced by the fluctuating southward field components upstream of the
third shock, the second one by the southward field components downstream
of the third shock, and the major one by the southward field components
within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I
agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious
geo-effectiveness, as you can see from the data. The fourth shock in the
plot was associated with the June 22 M6.5 eruption, and it was beginning
to overtake the ICME from behind at 1 AU. Another eruption on June 25
(M7.9) also produced a shock that impacted Earth (not shown in the plot),
but it didn't produce geo-effectiveness either.

Also we see another 2 proceeding shocks as pointed out by Noe. These
multiple preceding shocks and sheaths may precondition the magnetosphere
for the growth of a strong geomagnetic storm (say, by feeding plasma to
the plasma sheet). I am not sure if the third shock was propagating into a
preceding ejecta, because I don't see clear ICME signatures upstream of
the shock. The fluctuating southward fields upstream of the third shock
may be produced by amplification of the ambient fields by the preceding
shocks.

Best,
Ying

On Mon, July 13, 2015 2:00 pm, Nariaki Nitta wrote:
> Dave,
>
> I normally look for shocks rather than ICMEs on ACE RTSW data. I don't
> think your M6.5 flare (on 22 June) had to do with the big Dst decrease
> during 22-23 June. The CME associated with the M6.5 flare was fast but
> not geo-effective (see
> https://twitter.com/halocme/status/613835532116828160). Different
> thoughts?
>
> Nariaki
>
> David Webb wrote on 13.07.15 13:48:
>
>> Nariaki,
>>
>> Of course I knew you would have it figured out! I guess we all need to
>> get on Twitter- wonder when NOAA will start sending out "official"
>> forecasts via Twitter!! Do I need to be a Twitter "subscriber" to get
>> your tweets?
>>
>> So I assume you ID the 3 CMEs as the shock arrival times. Again let's
>> be careful to differentiate shock from CME/ICME arrivals. Noe is saying
>> that one of the early shocks is propagating thru a preceding CME. And
>> what happened to the M6.5 event? What drove Dst to such low levels?
>>
>> Questions, questions,
>> Dave
>>
>> On Mon, Jul 13, 2015 at 4:29 PM, Nariaki Nitta <nitta@lmsal.com
>> <mailto:nitta@lmsal.com>> wrote:
>>
>> Dave,
>>
>> While you were preparing for SHINE, I tweeted a couple of time on
>> the road (therefore no detailed image analysis). There were at least four
>> eruptions during 18-22 June and the third one (associated with a M2
>> flare on 21 June) was a quite impressively circular CME
>> (https://twitter.com/halocme/status/612498918639677440), which I
>> think contributed the most to the geo-space effects (the CME arrived much
>> earlier than I had thought). Three CMEs seemed to arrive without
>> merging, see https://twitter.com/halocme/status/613216284675821568 (I
>> had to adjust the time axes of the plots). As of 23 June, it looked
>> possible that the Dst may hit -200 nT
>> (https://twitter.com/halocme/status/613227633074028544, indeed
>> auroras in California!). The M6.5 flare on 22 June was not associated
>> with a very geo-effective CME even though it arrived fast.
>>
>> The most recent storm (13 July) was much less impressive, even its
>> origin not being entirely clear.
>>
>> Nariaki
>>

Hi Dave et al.,

The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME, something I have been looking at recently. The larger dip on the 23rd is due to the following CME.
Wind data is attached. There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

Best,
Noé Lugaz

On Jul 13, 2015, at 3:26 PM, David Webb <david.webb@bc.edu> wrote:

Kyoto shows that this storm nearly reached "superstorm" (Dst<-200nT) level.
http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201506/dst1506.png

Many of us may have been distracted with our preparations for SHINE. Manuela first alerted us. Do we understand the cause-effect for it? Tamitha's recent video showed that it had significant geo-effects. There were apparently a series of flares/CMEs/EPs on June 21-22. Probably the storm was driven by the M7 event on June 22 but are we sure; was it a compound event?
-------

=Image Data=
[[File:20150623 satenv.gif]] 

[[File:Ace-mag-swepam-7-day.gif‎]] 

[[File:YL Wind ICMEs 21-25June2015.jpg]] 

Courtesy Yuming Wang.

=Video Data=

=References=

06/21/2015 15:30:00 UTC

2015-07-15T21:47:47Z

Davidwebb: /* Image Data */

File:YL Wind ICMEs 21-25June2015.jpg

2015-07-15T21:46:51Z

Davidwebb:

06/21/2015 15:30:00 UTC

2015-07-15T21:46:01Z

Davidwebb: /* Image Data */

=Comment Section=
*Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst near -200 (Hess) 

*WG4 EMAIL DISCUSSION ABOUT EVENT:

- July 14, 2015 
This event would perfectly fit as VarSITI Campaign Event. There are a lot of interesting aspects and the observations are quite nice to track the full chain of action and reaction when interacting with Earth (maybe also interesting for other VarSITI projects, e.g. ROSMIC?).
Cheers,
Manuela

This is a very interesting event indeed!

The discussion of multi-step storms reminds me of this 2002 paper. It has discussion on plasma sheet effect on ring current (and Dst) and in particular shows an interesting simulation results where two earlier Bs periods were removed and its effect to the total intensity of the storm studied. It seems that removing the earlier Bs peaks did not affect significantly to the total intensity of the storm.
http://onlinelibrary.wiley.com/doi/10.1029/2001JA000023/full

The strongest Bs intervals and the Dst minimum in the June event are indeed preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have lead to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

greetings,
Emilia

- July 13, 2015 
Hi Dave et al.,

Here is a plot combining Wind data and Dst. This is actually a multi-step
geomagnetic storm with the global minimum of -195 nT. The first dip was
produced by the fluctuating southward field components upstream of the
third shock, the second one by the southward field components downstream
of the third shock, and the major one by the southward field components
within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I
agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious
geo-effectiveness, as you can see from the data. The fourth shock in the
plot was associated with the June 22 M6.5 eruption, and it was beginning
to overtake the ICME from behind at 1 AU. Another eruption on June 25
(M7.9) also produced a shock that impacted Earth (not shown in the plot),
but it didn't produce geo-effectiveness either.

Also we see another 2 proceeding shocks as pointed out by Noe. These
multiple preceding shocks and sheaths may precondition the magnetosphere
for the growth of a strong geomagnetic storm (say, by feeding plasma to
the plasma sheet). I am not sure if the third shock was propagating into a
preceding ejecta, because I don't see clear ICME signatures upstream of
the shock. The fluctuating southward fields upstream of the third shock
may be produced by amplification of the ambient fields by the preceding
shocks.

Best,
Ying

On Mon, July 13, 2015 2:00 pm, Nariaki Nitta wrote:
> Dave,
>
> I normally look for shocks rather than ICMEs on ACE RTSW data. I don't
> think your M6.5 flare (on 22 June) had to do with the big Dst decrease
> during 22-23 June. The CME associated with the M6.5 flare was fast but
> not geo-effective (see
> https://twitter.com/halocme/status/613835532116828160). Different
> thoughts?
>
> Nariaki
>
> David Webb wrote on 13.07.15 13:48:
>
>> Nariaki,
>>
>> Of course I knew you would have it figured out! I guess we all need to
>> get on Twitter- wonder when NOAA will start sending out "official"
>> forecasts via Twitter!! Do I need to be a Twitter "subscriber" to get
>> your tweets?
>>
>> So I assume you ID the 3 CMEs as the shock arrival times. Again let's
>> be careful to differentiate shock from CME/ICME arrivals. Noe is saying
>> that one of the early shocks is propagating thru a preceding CME. And
>> what happened to the M6.5 event? What drove Dst to such low levels?
>>
>> Questions, questions,
>> Dave
>>
>> On Mon, Jul 13, 2015 at 4:29 PM, Nariaki Nitta <nitta@lmsal.com
>> <mailto:nitta@lmsal.com>> wrote:
>>
>> Dave,
>>
>> While you were preparing for SHINE, I tweeted a couple of time on
>> the road (therefore no detailed image analysis). There were at least four
>> eruptions during 18-22 June and the third one (associated with a M2
>> flare on 21 June) was a quite impressively circular CME
>> (https://twitter.com/halocme/status/612498918639677440), which I
>> think contributed the most to the geo-space effects (the CME arrived much
>> earlier than I had thought). Three CMEs seemed to arrive without
>> merging, see https://twitter.com/halocme/status/613216284675821568 (I
>> had to adjust the time axes of the plots). As of 23 June, it looked
>> possible that the Dst may hit -200 nT
>> (https://twitter.com/halocme/status/613227633074028544, indeed
>> auroras in California!). The M6.5 flare on 22 June was not associated
>> with a very geo-effective CME even though it arrived fast.
>>
>> The most recent storm (13 July) was much less impressive, even its
>> origin not being entirely clear.
>>
>> Nariaki
>>

Hi Dave et al.,

The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME, something I have been looking at recently. The larger dip on the 23rd is due to the following CME.
Wind data is attached. There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

Best,
Noé Lugaz

On Jul 13, 2015, at 3:26 PM, David Webb <david.webb@bc.edu> wrote:

Kyoto shows that this storm nearly reached "superstorm" (Dst<-200nT) level.
http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201506/dst1506.png

Many of us may have been distracted with our preparations for SHINE. Manuela first alerted us. Do we understand the cause-effect for it? Tamitha's recent video showed that it had significant geo-effects. There were apparently a series of flares/CMEs/EPs on June 21-22. Probably the storm was driven by the M7 event on June 22 but are we sure; was it a compound event?
-------

=Image Data=
[[File:20150623 satenv.gif]] 

[[File:Ace-mag-swepam-7-day.gif‎]] 

=Video Data=

=References=

06/21/2015 15:30:00 UTC

2015-07-15T21:43:23Z

Davidwebb: /* Image Data */

=Comment Section=
*Compound event with a series of shocks arriving over a 3-day span, and one likely magnetic cloud arriving around midnight on the 23rd, corresponding to a clear, symmetric halo CME on the 21st which drove the strongest of the shocks with a highly compressed magnetic field. Drove a powerful geomagnetic storm with a Dst near -200 (Hess) 

*WG4 EMAIL DISCUSSION ABOUT EVENT:

- July 14, 2015 
This event would perfectly fit as VarSITI Campaign Event. There are a lot of interesting aspects and the observations are quite nice to track the full chain of action and reaction when interacting with Earth (maybe also interesting for other VarSITI projects, e.g. ROSMIC?).
Cheers,
Manuela

This is a very interesting event indeed!

The discussion of multi-step storms reminds me of this 2002 paper. It has discussion on plasma sheet effect on ring current (and Dst) and in particular shows an interesting simulation results where two earlier Bs periods were removed and its effect to the total intensity of the storm studied. It seems that removing the earlier Bs peaks did not affect significantly to the total intensity of the storm.
http://onlinelibrary.wiley.com/doi/10.1029/2001JA000023/full

The strongest Bs intervals and the Dst minimum in the June event are indeed preceded by a mainly northward IMF and high density in CME sheath. Such conditions combined may have lead to particularly dense plasma sheath and enhanced the ring current later when strong Bs related to FR1 (in Ying's plot) arrived.

greetings,
Emilia

- July 13, 2015 
Hi Dave et al.,

Here is a plot combining Wind data and Dst. This is actually a multi-step
geomagnetic storm with the global minimum of -195 nT. The first dip was
produced by the fluctuating southward field components upstream of the
third shock, the second one by the southward field components downstream
of the third shock, and the major one by the southward field components
within the ICME associated with the June 21 M2.0 eruption (01:42 UT). I
agree with Nariaki that the June 22 M6.5 eruption didn't produce obvious
geo-effectiveness, as you can see from the data. The fourth shock in the
plot was associated with the June 22 M6.5 eruption, and it was beginning
to overtake the ICME from behind at 1 AU. Another eruption on June 25
(M7.9) also produced a shock that impacted Earth (not shown in the plot),
but it didn't produce geo-effectiveness either.

Also we see another 2 proceeding shocks as pointed out by Noe. These
multiple preceding shocks and sheaths may precondition the magnetosphere
for the growth of a strong geomagnetic storm (say, by feeding plasma to
the plasma sheet). I am not sure if the third shock was propagating into a
preceding ejecta, because I don't see clear ICME signatures upstream of
the shock. The fluctuating southward fields upstream of the third shock
may be produced by amplification of the ambient fields by the preceding
shocks.

Best,
Ying

On Mon, July 13, 2015 2:00 pm, Nariaki Nitta wrote:
> Dave,
>
> I normally look for shocks rather than ICMEs on ACE RTSW data. I don't
> think your M6.5 flare (on 22 June) had to do with the big Dst decrease
> during 22-23 June. The CME associated with the M6.5 flare was fast but
> not geo-effective (see
> https://twitter.com/halocme/status/613835532116828160). Different
> thoughts?
>
> Nariaki
>
> David Webb wrote on 13.07.15 13:48:
>
>> Nariaki,
>>
>> Of course I knew you would have it figured out! I guess we all need to
>> get on Twitter- wonder when NOAA will start sending out "official"
>> forecasts via Twitter!! Do I need to be a Twitter "subscriber" to get
>> your tweets?
>>
>> So I assume you ID the 3 CMEs as the shock arrival times. Again let's
>> be careful to differentiate shock from CME/ICME arrivals. Noe is saying
>> that one of the early shocks is propagating thru a preceding CME. And
>> what happened to the M6.5 event? What drove Dst to such low levels?
>>
>> Questions, questions,
>> Dave
>>
>> On Mon, Jul 13, 2015 at 4:29 PM, Nariaki Nitta <nitta@lmsal.com
>> <mailto:nitta@lmsal.com>> wrote:
>>
>> Dave,
>>
>> While you were preparing for SHINE, I tweeted a couple of time on
>> the road (therefore no detailed image analysis). There were at least four
>> eruptions during 18-22 June and the third one (associated with a M2
>> flare on 21 June) was a quite impressively circular CME
>> (https://twitter.com/halocme/status/612498918639677440), which I
>> think contributed the most to the geo-space effects (the CME arrived much
>> earlier than I had thought). Three CMEs seemed to arrive without
>> merging, see https://twitter.com/halocme/status/613216284675821568 (I
>> had to adjust the time axes of the plots). As of 23 June, it looked
>> possible that the Dst may hit -200 nT
>> (https://twitter.com/halocme/status/613227633074028544, indeed
>> auroras in California!). The M6.5 flare on 22 June was not associated
>> with a very geo-effective CME even though it arrived fast.
>>
>> The most recent storm (13 July) was much less impressive, even its
>> origin not being entirely clear.
>>
>> Nariaki
>>

Hi Dave et al.,

The first dip on June 22nd (~-150 nT) is clearly due to a shock propagating in preceding CME, something I have been looking at recently. The larger dip on the 23rd is due to the following CME.
Wind data is attached. There are three probable fast forward shocks in 30 hours from 06/21 at 15UT to 06/22 at 18UT. The third shock combines a very large increase in dynamic pressure and a large short-duration southward Bz; it must have really compressed the magnetosphere like crazy. The CME on the 23rd had extremely low density and back of the envelope estimate shows that the solar wind may have had a Mach number of ~1.

Best,
Noé Lugaz

On Jul 13, 2015, at 3:26 PM, David Webb <david.webb@bc.edu> wrote:

Kyoto shows that this storm nearly reached "superstorm" (Dst<-200nT) level.
http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/201506/dst1506.png

Many of us may have been distracted with our preparations for SHINE. Manuela first alerted us. Do we understand the cause-effect for it? Tamitha's recent video showed that it had significant geo-effects. There were apparently a series of flares/CMEs/EPs on June 21-22. Probably the storm was driven by the M7 event on June 22 but are we sure; was it a compound event?
-------

=Image Data=
[[File:20150623 satenv.gif]] 

[[Ace-mag-swepam-7-day.gif‎]] 

=Video Data=

=References=

File:Ace-mag-swepam-7-day.gif

2015-07-15T21:42:23Z

Davidwebb:

06/21/2015 15:30:00 UTC

2015-07-15T21:41:15Z

Davidwebb: /* Image Data */

File:20150623 satenv.gif

2015-07-15T21:40:18Z

Davidwebb: