Working Group 1

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?

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

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

How well can we forecast the ICME parameters from remote observations?

What is the cause of "stealth" CMEs, i.e., CMEs without clear surface signature?

What is the cause of "problematic" ICMEs, i.e., ICMEs without clear CME counterparts near the Sun?

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?

Special Events (with WG3 and WG4)

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

Techniques, Methodology

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)