Difference between revisions of "Working Group 1"

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(→‎Definition and terminology of ICMEs?)
(→‎Definition and terminology of ICMEs?)
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*** paper by Alex Rouillard (2011 JASTO) discussed the nomenclature
 
*** paper by Alex Rouillard (2011 JASTO) discussed the nomenclature
  
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What are the main CME parameters which can be derived from remote and in situ CME observations?
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===What are the main CME parameters which can be derived from remote and in situ CME observations?===
  
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How reliably can we link solar to in situ CME observations?
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===How reliably can we link solar to in situ CME observations?===
  
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How well can we forecast the ICME parameters from remote observations?
+
===How well can we forecast the ICME parameters from remote observations? Especially, the Bs===
  
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What is the cause of "stealth" CMEs, i.e., CMEs without clear surface signature?
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===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)
  
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What is the cause of "problematic" ICMEs, i.e., ICMEs without clear CME counterparts near the Sun?
+
===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
  
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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?
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===Are there limb CMEs that arrive at the Earth (the driver)?===
 +
 
 +
===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
 +
** lack of Bs
 +
** may just disappear or "dissolve" (???)
  
 
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Revision as of 05:04, 17 June 2013

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


Scientific Objectives


  • 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


Scientific Questions


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 Alex Rouillard (2011 JASTO) 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

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

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

.........


Special Events (with WG3 simulation and WG4 campaign events)


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
  1. late July to early August 2010
  2. February 2011
  3. early March 2012
  4. July 2012
  • ....


Methods


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")
  • ....


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.
  • ....


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:
  1. minimum variance analysis
  2. Grad-Shafranov method (non-force-free)
  3. force-free cylindrical flux ropes
  4. new models?
  • ....


How to measure the geomagnetic effects?

  • geomagnetic indices (Dst, Kp)
  • ....


Progress at workshop in Hvar June 2013


WG1 Goals for Hvar workshop

  • understand in detail the parameters derived from observations
  • learn how to use the wiki: for discussions, and to upload and link data
  • verify the master list, identify and discuss unclear events (with WG3 simulation and WG4 campaign events)
  • ....


WG1 Presentations at the Hvar Workshop 2013

  • 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


Future Plan

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