The low to mid latitude thermospheric response to solar wind forcing during 2002-2005 storms as observed by the Champ/Star accelerometer

Abstract : Total thermospheric density retrieved from the STAR accelerometer measurements made onboard CHAMP for years 2002 to 2005 is used to define a disturbance coefficient that characterizes the global perturbation of the low to mid latitude thermosphere associated to solar wind forcing. No projection of satellite data at a given altitude is performed, meaning that our results do not depend on a priori hypothesis on the atmospheric scale height. We focused on thermospheric storms that correspond to a global increase in thermospheric density at mid and low latitudes by more than 100 39 events are identified in our data base with a maximum number of occurrences in 2005. We will present a comparative study of these thermospheric storms in relation with magnetic activity indices and solar wind parameters at L1.