Working Group 5

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This page is a summary of Working Group 5 (WG5) led by Spiros Patsourakos (Greece). WG5 is dedicated to predicting the southern magnetic field component of CMEs at 1 AU.



WG5 Statement

The presence of southward magnetic fields (Bs) in ICMEs is the most important factor in producing geomagnetic storms. The challenge is that direct observations of the magnetic field vectors near the Sun are extremely limited: currently possible only in the photosphere/chromosphere in the solar end and by in-situ observations at 1 AU. WG5 aims to understand and reconstruct the possible magnetic flux rope structure of CMEs/ICMEs from observations and models. It also aims to predict the intensity and possibly the duration of the Bs in ICMEs upon arrival at Earth.


Methodology

  • Deduce/estimate near-Sun |B| of CMEs (e.g., radio, coronal polarization, flux-rope model, magnetic helicity, CME-driven shocks)
  • Deduce near-Sun orientation of CMEs (e.g., geometrical CME modeling)
  • Propagate near-Sun |B| to 1 AU (e.g., theoretical/observational scaling-laws, MHD modeling)
  • Propagate near-Sun orientation to 1 AU (MHD modeling)
  • Compare predictions with observations at 1 AU (MC fitting)

Preliminary Work Plan


  • Find suitable datasets for near-Sun |B| field calculations applicable to as many of the available methods as possible --- start with events already analysed by various team members ----coordinate w/ the data and campaign WGs (yrs 1-2)
  • Assess the pros & cons of the various methods of near-Sun |B| determination -- coordinate w/ the theory and modeling WGs (yrs 1-2)
  • Apply methods (existing or improved) to a sample of CMEs and determine near-Sun |B| -> paper and list of events/data (yrs 2-3)
  • Extrapolate near-Sun |B| & orientation to 1 AU and compare w/ in-situ measurements and MC fittings ->paper and tables of pertinent data (yrs 3-4)

Current Action Items


  • Prepare a list of CMEs of which their near-Sun magnetic field has been already been deduced by at least one method.

Please fill in the table below by the end of August 2015. Events that you also plan to deduce their magnetic fields could be also included in the table. List of CMEs for WG5 Analysis