How to forecast geomagnetic storms reliably - The characteristics of storms in the rising phase of solar cycle 23
Abstract
The solar wind input parameters were studied for geomagnetic disturbed days in which Ap exceeded its average value by using plasma and magnetic field data from various near-Earth satellites. More than 270 events occurred during the time-period 1997 to 2002. The interplanetary and solar characteristics of these events have been summarised at http://alpha.sinp.msu.ru/apev. A unique identification of the corresponding solar sources was not possible for all of the events, but in general they could be classified based on SOHO white-light and EUV observations taken by the LASCO/EIT telescopes into disturbances caused by coronal hole flows and coronal mass ejections or interactions between them. Compression regions caused by stream interactions effects including compressed Alfven-waves are also an important cause of enhanced geomagnetic activity. Our results imply that the forecast of an individual storms does not only require sufficient real-time observations of the solar corona, but as well modelling of the heliospheric situation, finally taking into account a seasonal dependence of the coupling efficiency of the IMF with the Earth’s magnetosphere. The work is supported by grants INTAS-ESA 99-00727 and INTAS 00-752 .
- Publication:
-
EGS - AGU - EUG Joint Assembly
- Pub Date:
- April 2003
- Bibcode:
- 2003EAEJA.....2018B