"Substorms" in the corona and preliminary results from SOHO

A discussion of eruptive processes in the solar atmosphere is given with special attention to features which have similarities to physical processes occuring during magnetospheric substorms. Though there is no one-to-to-one correspondence between substorms and solar eruptions, the basic physical processes playing major roles in both phenomena, like magnetic reconnection, are actually similar. Since the magnetosphere is accessible to in situ measurements by spacecraft, it is an ideal system to test ideas which might also apply to the solar corona or other astrophysical objects. In the present situation, with the SOHO spacecraft starting its observations of the sun and others, like the YOHKOH spacecraft, which have been fully operational for several years, there is an excellent opportunity to scrutinize those ideas in the solar corona.