Abstract
Effects of the interplanetary magnetic field (IMF), particularly its polarity, on the lower thermosphere are briefly reviewed. A fairly well-known indirect correlation is that both long-lasting southward IMF and the boundary between eastward and westward fields often cause magnetospheric disturbances which produce storm related thermospheric variations. A direct correlation is that the IMF westward (or eastward) component produces clockwise (or counterclockwise) circular electric currents in the lower thermosphere over the polar region. Computer simulation studies of a possible mechanism of this effect are presented. IMF effects on the change of the magnetospheric configurations without any appreciable thermospheric variation are also included, and suggestions for future investigations are provided.
