STUDY OF PLASMASPHERE-IONOSPHERE COUPLING FLUXES

An attempt has been made to study ionosphere-plasmasphere coupling by analysing whistler data observed at the low-latitude Indian stations o f Varanasi (geomag. iat. 14 degrees 55'N, geomag. long. 153 degrees 59 'E), Nainital (geomag. lat. 19 degrees 1'N, geomag. long. 149 degrees 45'E) and Gulmarg (geomag. lat. 24 degrees 10'N, geomag. long. 147 deg rees 9'E). The change in dispersion of whistlers with time is used to deduce the change in electron content of a flux tube. The data set pre sented in this paper clearly establishes the downward transport of ion ization from the plasmasphere to the ionosphere and, hence, establishe s the importance of ionosphere-plasmasphere coupling at low latitudes. (C) 1997 Elsevier Science Ltd.