Estimating the contribution from different ionospheric regions to the TEC response to the solar flares using data from the international GPS network

摘要

This paper proposes a new method for estimating the contribution fromdifferent ionospheric regions to the response of total electron contentvariations to the solar flare which uses the effect of partial shadowing of theatmosphere by the terrestrial globe. The study uses GPS stations located nearthe boundary of the shadow on the ground in the nightside hemisphere. The beamsbetween the satellite-borne transmitter and the receiver on the ground forthese stations pass partially through the atmosphere lying in the region oftotal shadow and partially through the illuminated atmosphere. The analysis ofthe ionospheric effect of a powerful solar flare of class X5.7/3B that wasrecorded on July 14, 2000 (10:24 UT, N22W07) in quiet geomagnetic conditions (Dst=-10 nT) hasshown that about 20% of the TEC increase correspond to the ionospheric regionlying below 100 km, about 5% refer to the ionospheric E-region (100-140 km),about 30% correspond to the F1-region (140-200 km), and about 30% to regionslying above 300 km.