07/14/2012 17:00:00 UTC

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.

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• • 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:

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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.

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Heliospheric Imaging

CME track observed in STEREO-A Jmap with SATPLOT software: (C. Moestl)

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results of geometrical modeling (C. Moestl):

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Jmaps along the CME leading edge position (about <math>7^{\circ}</math> S of the ecliptic) from STEREO A and B

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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.

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

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 [1]

• GOES X-RAY FLUX

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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

AIA-94
AIA-171
AIA-211
HMI B

STEREO observations

COR2A
COR2B
HI1A
HI1B
HI2A
HI2B

PROBA2 observations

PROBA2 SWAP 174
PROBA2 SWAP 174 Difference Movie

References

(Collected by Xin Cheng and Dave Webb)

1. Dudik, J. et al., ApJ, 2014,Slipping Magnetic Reconnection during an X-class Solar Flare Observed by SDO/AIA

2. Cheng, X. et al., ApJ, 2014,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,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.