Observations of the MHD and helioseismic
responses to flare energy-release events
Alexander Kosovichev
Recent observations of solar flares with SOHO/MDI led to
discovery of new powerful helioseismic events ("sunquakes"),
caused by the impact of high-energy particles.
These observations provide important information about
the physics of the interaction between high-energy particles
and plasma, hydrodynamics of the energy release,
and interaction of MHD waves with sunspots, as well as
opportunities for developing new helioseismic
diagnostics of flaring active regions.
The MDI observations have revealed new unexpected features
of these events, such as a strong anisotropy of the wave
amplitude, extended and multiple sources correlated with
hard X-ray and white-light emission. However, the relatively
low spatial and tempposter resolution of the MDI instrument
does not allow us to investigate many interesting details of
the sunquake sources and MHD wave propagation. The initial
shocks, generated by high-energy particles, are developed
on the time scale of 1-2 min, and spatial scales of
1-2 arcsec, also the seismic response waves have significant
power above 6 mHz well above the standard helioseismology range.
I present the recent results of the sunquake investigations
using MDI and RHESSI data, and propose a program of simultaneous
observations with SOT, XRT and EIS for investigation of the
energy-release events and their impacts.
Correspondence
Alexander Kosoviche (AKosovichev@solar.stanford.edu), Stanford University
presentation
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