PC INDEX ANALYSES AND ITS RELATION TO AURORAL ELECTROJET INDICES
ON BASE OF THE HIGH LATITUDE GEOMAGNETIC VARIATION MODEL
    
V.A. Popov, S.A. Golyshev, A.E. Levitin  (IZMIRAN, Troitsk, Russia)

PC index was suggested by its authors as a quantitative characteristic of the
transpolar current. The relations of magnetic field values on polar cap 
station (Thule) with the solar wind parameters are used for that purpose. As 
a matter of fact the inverse problem is under consideration: the combination of 
solar wind parameters (V-Bz-SinBy/Bx) are being found on base of geomagnetic 
data.

IZMIRAN electromagnetic model (IZMEM) is based on the geomagnetic field - 
solar wind parameters correlation analyses. So it lets to calculate components 
of the magnetic field perturbation in arbitrary point of the  polar cap for any 
IMF conditions. IZMEM lets to calculate the transpolar current as well. In such 
a way the PC index quality could be evaluated. Moreover the modeling lets to 
improve index taking into account additional magnetic observatories data and 
to exam the PC index and AE indices interrelations. [This paper has been supported 
by the Russian Foundation for Fundamental research, grant 99-05-64296].