On Geomagnetic Activity Forecasting

摘要

The mean-term forecasting of geomagnetic activity has been carried out at the geomagnetic observatory "Lviv" during 2001-2005. The forecasts are based on 27-day recurrence of solar and geomagnetic activity, their changes during the solar cycles and existence of the so-called "active longitudes on the Sun". The existence of the "active longitudes on the Sun", especially during the decay phase of solar cycle, allows to improve the forecasting. The successful forecast of geomagnetic storms was in about 65% of cases. An accuracy of the forecast increases with decreasing geomagnetic activity.