scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...

STP12 Abstracts
Berlin, 12 - 16 July 2010
SCOSTEP Symposium 2010
Statistical Properties of the Most Powerful Solar and Heliospheric Events Related to
Strong Magnetospheric Disturbances
Yakovchouk Olesya
1) Institute of Nuclear Physics, Moscow State University, Moscow, Russia; 2) Department of Physical
Sciences, University of Oulu, Finland
The study of space weather and solar-terrestrial relations remain important from scientific and
practical points of view. The investigation of extreme solar and hemispheric events is related
with following difficulties: 1) the library of extreme events is small: extreme events are rather
rare by definition; 2) the reliable theoretical models of extreme events are still not available.
Nowadays various indexes are used for the description of parameters and a prediction of
space weather condition. In our work we took the NOAA classification. The critical
parameters were the X-ray flux (parameter R), solar proton flux (parameter S) and
geomagnetic disturbance level (parameter G). The number of disturbances increases
exponentially with a decreasing of a level of S and G parameters. Probability of events with a
small occurrence frequency is overstated for data set in comparison with the theoretical von
Neumann model of a random process for all parameters, especially for R.