On the response of exospheric temperature on venus to solar wind conditions

Abstract

Exospheric temperatures (T_ex) inferred from in-situ measurements of neutral densities by the Pioneer Venus Orbiter have been analyzed to examine any possible dependence on solar wind dynamic pressure (P_sw). We do not find any linear relationship between P_sw and T_ex. However, on one occasion when P_sw was unusually high for a prolonged period, an unmistakable temperature enhancement was observed. Minor enhancements of T_ex were also observed in a few other cases, with sustained but moderately high P_sw.