Esro 4 model of global thermospheric composition and temperatures during times of low solar activity

This is the authors' abstract. We don't add key points for this paper.

We present an empirical model of global exospheric temperatures and densities of neutral constituents, based on data from 228 geomagnetically quiet days during the operation of the Esro 4 gas analyzer (mean A p = 7). By means of an expansion in spherical harmonics the model infers exospheric temperatures from both the measured N 2 and Ar densities. O and He densities are presented as extrapolated density distributions at 120 km altitude. The Esro 4 model complements the similar Ogo 6 mass spectrometer model with observations at considerably lower altitudes (240‐320 km) and lower levels of solar activity Inferred exospheric temperatures are typically 5‐9% below Ogo 6 model values for F 10.7 = 120.