Institute of Space Science, National Central University, Chung-Li, Taiwan
Analysis of the magnetosphere-ionosphere coupling has been made for the recurrent magnetic storm on 22 July 2009. It was found large enhancements of energetic (>30 keV) electrons below the radiation belt in the forbidden zone, so-called forbidden energetic electrons (FEE), as observed by NOAA/POES and GOSAT satellites. The FEE enhancements produced an additional ionization in the topside ionosphere, which was found as a positive ionospheric storm of ~15 TECU at low latitudes from COMIC/FORMOSAT-3 radio occultation measurements and ground-based GPS network. We discuss relative contributions of the FEE ionization effect and other standard mechanisms to the positive ionospheric storm observed.