The relationship between CME momenta and magnetic forces

Thursday, 18 December 2014
Yan Li, Benjamin J Lynch, Brian T Welsch and David John Bercik, University of California Berkeley, Berkeley, CA, United States
Free magnetic energy is the energy source of solar flares and CMEs. At the
initiation of a CME, the free magnetic energy converts to kinetic energy
and few other types of energy. Observable magnetic field sudden changes have
been found at the onset of flares. The Lorentz force around the onset of
a flare have been formulated in recent studies and can be estimated
using photospheric vector magnetic field data. It is proposed that
outward Lorentz force impulses could be related to CME momenta.
We analyze about 30 CMEs and their source region magnetic fields.
The best vector magnetic field data are observed for active regions near
the center of the solar disk. We first select CMEs that appear to be halo
or partial halo CMEs in the LASCO images, and then we use STEREO SECCHI COR2
white light images to estimate CME mass and speed. We then estimate
the Lorentz forces in the source active regions at the flare onset
using SDO HMI photosheric vector magnetic field data.
We report our work in progress and describe our analyses.