Ionospheric effects on the thermosphere during high solar activity

Abstract

In order to study the effects of ionospheric plasma densities on the thermosphere for low solar activity, the electron and O+ densities in the Thermosphere Ionosphere Nested Grid (TING) model were replaced by electron densities from the Global Assimilation of Ionospheric Measurements (GAIM) model at pressure level z = 0 (about 230 km altitude) and above for the period April 1-4, 2004 (Jee et al., 2008). In their study, it was found that the ingestion of the GAIM electron densities into the TING model had little effect on the neutral temperature and composition during the quiet period before the storm, but there were noticeable global effects on the neutral winds, mainly as a result of changes in the ion drag force. During disturbed periods, changed electron densities produced much more significant effects on the global thermosphere. The increased auroral electron densities enhanced the Joule heating rate, in addition to the ion drag, which resulted in significant global changes not only in the neutral winds, but also in the neutral temperature and composition. As a continuation of this study, we selected April 2002 to perform a similar study for high solar activity. This period is very similar to the April 2004 for our previous study except for the solar activity condition. Similar methodology will be applied for this period by using the same models and the preliminary results will be presented.