HR: 1340h
AN: SM43A-1149    [Abstracts]
TI: On Short-Time Prediction of Geomagnetic Activity
AU: * Lyatsky, W
EM: lyatsky@cspar.uah.edu
AF: Alabama A&M University, 4900 Meridian st., Huntsville, AL 35762 United States
AU: Tan, A
EM: ATAN@aamu.edu
AF: Alabama A&M University, 4900 Meridian st., Huntsville, AL 35762 United States
AB: Prediction of geomagnetic activity is one of important tasks related to Space Weather Program. Global geomagnetic activity is controlled by solar wind parameters, the conditions in the magnetosphere and ionosphere (which are dependent on previous geomagnetic activity), season, and universal time. We developed an approach, which allowed us to improve significantly the reliability of short-time geomagnetic activity forecast. We used a solar wind-geomagnetic activity coupling function that is some different from the Akasofu parameter and proportional to V*f(Bz) where V is solar wind speed and f(Bz) is a step-like function dependent on the IMF Bz component and season/UT conditions. The correlation coefficient for hourly values of this coupling function and the AL index is higher than 0.8. Moreover, it increases significantly if instead of the AL index we used a geomagnetic activity index including geomagnetic disturbances at both high and low latitudes. Such index shows the excellent correlation with the solar wind-geomagnetic activity coupling function; the correlation coefficient is about 0.9 and higher.
DE: 2134 Interplanetary magnetic fields
DE: 2447 Modeling and forecasting
DE: 2722 Forecasting
SC: SPA-Magnetospheric Physics [SM]
MN: 2004 AGU Fall Meeting