The search for ion-neutral coupling and Joule heating in the polar ca

It is commonly postulated that thermal expansion of the neutral atmosphere due to Joule heating may be responsible for anomalously-large neutral densities experienced by satellites near the Earth's poles. Direct measurements of Joule heating rates are difficult due to the dependence on the neutral wind, and .In a recent paper, we investigated heating rates in the auroral regions using neutral measurements from the Poker Flat Scanning Doppler Imager (SDI) and ion velocities from SuperDARN. We have now applied that technique to data from the Antarctic SDIs in order to better study ion-neutral coupling and Joule heating in the polar cap. Preliminary results suggest that ion-neutral coupling is much less common due to lower ion velocities and less precipitation outside of the auroral region however, the stronger neutral winds due to thermal gradients across the pole serve to buoy the Joule heating rate even when ion velocities are small. We present ion-neutral coupling and Joule heating measurements during both isolated and extended periods of geomagnetic activity.