View source for Working Group 1

Data group led by Jie Zhang (USA) and Christian Moestl (Austria)



=='''Scientific Objectives'''==
<br/>
*'''Identify''' all Earth-Affecting ICMEs during the STEREO era (2007-today)
*'''Track''' these events from the Sun to the Earth, and fully measure, characterize and quantify their properties and evolution from the Sun to the Earth
*Provide a comprehensive event '''database''' for statistical study, for creating empirical evolution and prediction models, for theoretical understanding, and for comparing and validating numerical models
<br/>

=='''Scientific Questions'''==

<br/>
===What are the criteria of Earth-affecting CMEs?===
*ICME signatures: primarily based on the strength and duration of magnetic field, low temperature and low density using ACE data.
**geo-effectiveness events will be a subset of the list (largely depending on the Bs)

===Definition and terminology of ICMEs?===
*ICME includes entire transient interval, including the shock, shock sheath, ICME ejectum
**ICME arrival time means the arrival of the shock and the disturbance (commonly used)
**magnetic driver arrival time meas the arrival of the ejectum,  magnetic cloud (flux rope), magnetic-cloud-like (from modeling/understanding perspective)
*** magnetic driver versus CME ejecta (how to choose the term?)
*** paper by Alexis Rouillard (2011 JASTP) discussed the nomenclature

===What are the main CME parameters which can be derived from remote and in situ CME observations?===

===How reliably can we link solar to in situ CME observations?===

===How well can we forecast the ICME parameters from remote observations? Especially, the Bs===

===What is the cause of "stealth" CMEs? ===
*"stealth CME" means that a CME clearly in coronagraph images, but no apparent signatures in coronal disk images, i.e., no flare, no filament eruption, no dimming/wave
*frontside CME may be mistaken as a backside CME; a space weather program for mis-alarming (true negative event)

===What is the cause of "problematic" ICMEs?===
*"Problematic ICMEs" mean that an ICME clearly shown up in in-situ, but there is no apparent front-side halo CME counterpart in the search window (five days)
* "stealth CME" is a subset of "problematic ICME"
* other problematic ICME candidates are extremely faint events in LASCO and SECCHI

===Can we find names for all types of CMEs lacking signatures in any of the three datasets: disk, coronagraph, in situ?===
a first try from Chris Moestl:
there are 2^3=8 possible combinations: (no, no, no excluded; yes, yes, yes, is a "classic" CME), leaves 6:
*stealth CME:                            disk (no), coronagraph (yes), in situ (yes)
*stealth CME not arriving:         disk (no), coronagraph (yes), in situ (no): essentially a stealth CME which either does not arrive at or misses in situ 
*problematic ICME:                   disk (no?), coronagraph (no), in situ (yes)
*??? another type of problematic ICME:                  disk (yes), coronagraph (no), in situ (yes): does this kind of event exist?
*confined flare:                        disk (yes), coronagraph (no), in situ (no)
*classic CME not arriving:         disk (yes), coronagraph (yes), in situ (no): essentially a classic CME which either does not arrive at or misses in situ

===Are there limb CMEs that arrive at the Earth (the driver)?===

=== Can CME cross the heliospheric current sheet? ===

===Can we find examples of front-side full halo CMEs in C2, but have no ICME signatures at 1 AU? Does this kind of event exist or not?===
*an issue for space weather false-alarming? reasons
** deflection
***location of coronal holes
***effect of heliospheric current sheet

** rotation

** lack of Bs
** may just disappear or "dissolve" (???)

===Interacting CMEs and ICMEs?===
*what are the signatures?
*how the evolution is affected?
*how geo-effectiveness is affected?


===''energetic particles''===
 
=== ..... .===
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== '''Special Events (with WG3 simulation and WG4 campaign events)''' ==

<br/>
===What are event periods which need special attention for linking solar to in situ observations?===
*use simulation results from WG3, insights from WG4
*e.g. interacting events, very fast or very slow CMEs, or other special properties

<br/>
'''happy textbook event:'''
*12-14 July 2012
'''interesting event''': CME with very slowly erupting signatures (dimming, cavity); traveling in about 3 days from Sun to 1 AU (although low initial and low arrival speed); also caused a geomagnetic storm (Dst min around -100 nT)
*5-8 Oct 2012

<br/>
nice interaction of 2 CMEs:
*15-18 February 2011

other more complicated event periods:
*early March 2012
*late July to early August 2010 (many analyses already published) <br/>
*....

== '''Methods''' ==

<br/>
===How to measure 3-D geometric and kinematic properties of CMEs in the corona, e.g., FOVs of COR1, COR2 and HI-1?===
*croissant modeling a la Thernisien et al. (software available in IDL SolarSoft: "rtsccguicloud")
*....
<br/>

===How to measure 3-D geometric and kinematic properties of CMEs far from the Sun, e.g., FOVs of HI-2?===
*Geometrical modeling, approximating the CME front with geometrical shapes (points, circles). The IDL SolarSoft SATPLOT software can be used to extract and model time-elongation tracks of CMEs from STEREO/COR2/HI1/HI2 Jmaps.
*....
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===How to reconstruct the 3-D structure of ICMEs from in-situ observations?===
*shock analysis
*sizes of sheath regions, magnetic clouds
*categorization of magnetic structures into magnetic clouds, magnetic flux ropes, magnetic cloud-like, ejecta, complex ejecta
*flux rope modeling:
#minimum variance analysis 
#Grad-Shafranov method (non-force-free)
#force-free cylindrical flux ropes
#new models?
*....
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=== How to measure the geomagnetic effects? ===

*geomagnetic indices (Dst, Kp)
*....
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=='''Progress at workshop in Hvar June 2013'''==
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===WG1 tasks for Hvar workshop===
#'''verify the master list, clean the list''' (only events in 2012 left)
#discuss what parameters will be in the event list? who does what?
##how to determine the velocity? especially for the true 3-D velocity?
##elongation angle to distance and velocity?
##what is the acceleration profile of CMEs through the interplanetary space? (for theoretical analysis)
##radio observation
#identify special events: happy one and surprising ones (done, more?)
#address the question of stealth CMEs, and problematic ICMEs 
#ask WG2/3 for inputs on special events (!)
#
<br/>

=== WG1 + WG4 ===
*happy event: July 12 - 14, 2012
*"stealth" event: Oct. 5 - 8, 2012

=== WG1 Presentations at the Hvar Workshop 2013 ===
All presentations from the workshop can be found at [[ISEST Presentations]]
*Ewa Chmielewska: Solar eruptions observed by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory
*Yuming Wang: Do we need to correct projection effect for halo CMEs in terms of space weather forecasting?
*Philippe Lamy: ARTEMIS II: A Second Generation Catalog of LASCO Coronal Mass Ejections
*Li Feng: Reconstruct the 3D CME morphology with a mask-fitting method
*Manuela Temmer: Interaction process of the CME-CME event from February 14-15, 2011 
*Chenglong Shen: Deflected propagation of the 2008 September 13 CME in the heliosphere
*Christian Moestl: Connecting remote to in situ observations of 22 coronal mass ejections from the Sun to 1 AU
*Alexis Ruffenach: Statistical analysis of magnetic cloud erosion by magnetic reconnection
*Nadya Nikolaeva: Magnetic storm generation by various types of solar wind: event catalog, modeling and prediction

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=='''Future Plan'''==
===populate the event data (platform)===
short term goals:
*list of SEPs at Earth, triangulation analysis and SEP intensity
*discussions on the the two chosen events (12-14 July 2012, 5-8 October 2012) -> on wiki discussion site (top left of this webpage)
*provide more data one the two chosen "focus events" (all groups)
*add pressure to possibly over-expanding events
*invite people for global field extrapolations (only for campaign events?)
*what do participants want to do with the event list?


long term goals:
*add events to the "Event Data" list
*provide data on other events in "Event Data"
*add charge state measurements
*add pressure to possibly over-expanding events

===remaining questions (forum)===

*email updates (how often) and telecons