Possible Cosmic Ray Using for Forecasting of Major Geo- magnetic Storms, Accompanied by Forbush-Effects

We present developing of methods for forecasting on the basis of NM hourly on-line data geomagnetic storms accompanied by Forbush-effects. These geomagnetic storms are dangerous for technology (influence on power systems, on spacecraft operations, on HF radio-communications and others) and people health. We show that for especially dangerous geomagnetic storms can be used global-spectrographic method if on-line will be available 35–40 NM of world-wide net. In this case for each hour can be determined CR anisotropy vector, and the specifically behavior of this vector before SC of geomagnetic storms can be used as important factor for forecast. The second factor is specifically behavior of CR density for about 30–15 hours before SC (pre-increase effect, caused mainly by galactic CR particles acceleration during interaction with shock wave moved from the Sun). The third factor is effect of cosmic ray pre-decreasing, caused by magnetic connection of the Earth with the region behind the shock wave. We demonstrate developing methods on several examples of major geomagnetic storms. This research is partly supported by the EU INTAS grant 00-0810.