The First MURI Case Study: 
A Flare and CME from NOAA 8210


To achieve the goals of the the MURI project, we have to study CME mechanisms both in the low solar corona and in the interplanetary medium. We have chosen NOAA 8210, observed from April 28 to May 2, 1998 for this combined analysis. Check out Yan Li's web page to see the from the Sun's photosphere to the interplanetary medium. 

This active region was chosen for study because it had many interesting features that were well observed in the photosphere, corona, and interplanetary medium.

Photospheric Features

This active region had several desireable properties:
  • Continuum images of AR8210 (see Fig. 1 top left) show that this active region includes sunspot umbrae of opposite polarities (see Fig. 3 top right) within a single penubra. This configuration,known as a "delta" configuration, is known to be associated with major flares.
  • Flux emergence and motions of sunspots are observed (see Barry Labonte's movies);
  • A large number of vector magnetograms are available both before and after the flare and CME;
  • A map of the Full Sun longitudinal magnetic field is provided by the MDI/SOHO magnetograph.

    •  

     
    Fig. 1 (click to enlarge): Continuum image (top left), longitudinal (top right), transverse (bottom left) and azimuthal (bottom right) components of the magnetic field B (quicklook IVM (Mees Solar Observatory) of AR8210, 05/01/1998, 17:42 UT)  Fig. 2 (click to enlarge): Halo CME observed by LASCO C3 Coronograph (SOHO) on May 1, 1998 

    Coronal Features

  • AR8210 is well observed by coronal instruments such as CDS/SOHO, EIT/SOHO, SXT/Yohkoh, LASCO/SOHO (see Fig. 2);
  • A flare is observed in AR8210 near the disk center on May 1, 1998
  • A halo CME (toward the Earth) is associated to the flare of May 1, 1998 (Fig. 2);

    • Interplanetary Features

    see Yan Li's web page for Solar Energetic Particler events and solar wind data (ACE, GOES)
     
      All these observations will help us carry out a comprehensive analysis of this eruptive event from the photosphere to the Earth. Vector magnetograms allow us to determine the 3D coronal magnetic configurations of the active region and its topological and energetic evolutions in time. The large scale magnetic field and the propagation of the CME can be studied using MDI magnetograms. In summary, for the MURI goals, AR8210 is THE active region for small and large scale modeling of magnetic fields in order to understand CMEs mechanisms and the consequences at the Earth. 

    MURI-MSU Nugget March 2002

    Stéphane Régnier, Richard Canfield, Dana Longcope