The SOHO/MDI observations of fast magnetic field variations associated with flares reveal a close temporal correlation of the irreversible magnetic field changes occurring in the bipolar flare region with the temporal behaviour of hard and soft X-ray emission. These are expected to be accountable for a primary magnetic energy release in the flare while the released energy is about 1% of the estimated energy being stored in the magnetic rope structure reconstructed for this active region (Yan et al., 2001). There are also reversible changes of magnetic field, called earlier as 'magnetic transients' or wave-like magnetic field variations, occurring in some unipolar flare regions. The 'transient' magnetic field changes are accompanied by the Moreton waves in the chromosphere and EIT waves in the corona. In some flares the magnetic field variations measured with MDI look like waves following the Moreton wave's fronts. These changes are likely to reflect the mechanisms of energy transport into deeper atmospheric layers by charged particles (electrons and/or protons).
|Original language||English (US)|
|Number of pages||4|
|Journal||European Space Agency, (Special Publication) ESA SP|
|State||Published - Jun 1 2002|
All Science Journal Classification (ASJC) codes
- Aerospace Engineering