Impact of electric field variability on Joule heating and thermospheric temperature and density

Abstract

A new quantitative empirical model of the high-latitude forcing of the thermosphere, which is the first empirical model with an electric field variability component consistent with the average electric field, is used with the NCAR-TIEGCM to investigate the influence of the electric field variability on the Joule heating, neutral temperature and density. The electric field variability increases the Joule heating by more than 100%, and significantly improves the agreement between the total Joule heating and integrated Poynting flux, while the horizontal distributions of the height-integrated Joule heating and the Poynting flux have some detailed differences in the polar cap and nightside regions. Including the electric field variability into the energy calculation results in significant changes in the neutral temperature and density. At 400 km, it causes a 120 K polar average temperature increase and the corresponding percentage difference of density is close to 30%. Copyright 2009 by the American Geophysical Union.