Ion-neutral coupling in the high-latitude F-layer from incoherent scatter and Fabry-Perot interferometer measurements

Since the auroral ionosphere provides an important energy sink for the magn etosphere, ionosphere-thermosphere coupling must be investigated when consi dering the energy budget of the ionosphere-magnetosphere coupling. We prese nt the first Scandinavian ground-based study of high-latitude F-region ion- neutral frictional heating where ion velocity and temperature are measured by the EISCAT incoherent scatter radar as well as neutral wind and temperat ure being measured simultaneously by a Fabry-Perot interferometer. A geomag netically active period (K-p = 7(-) - 5(-)) and quiet period (K-p = 0(+) - 0) were studied. Neglecting the neutral wind can result in errors of fricto nal heating estimates of 60% or more in the F-layer. About 96% of the local ion temperature enhancement over the neutral temperature is accounted for by ion-neutral, frictional heating.