Chatanika Radar observations relating to the latitudinal and local time variations of Joule heating

Observations of plasma convection made with the Chatanika incoherent scatter radar have been analyzed to give latitude/local time plots of the electric field contribution (E²) to thermospheric Joule heating. The data, which span the latitude range 56° to 75°Λ, show the presence of strong heating throughout the auroral regions. Of special interest are brief interludes of intense heating (>50 mW m−2) that are observed at nearly all local times and latitudes in response to magnetospheric disturbances. Further, there seem to be particular regions of the auroral oval where Joule heating seems to be continually enhanced above the broad background. The results of six 24 hour experiments are presented to illustrate summer (5) and winter conditions (1). A shorter eight hour experiment is also given to show the characteristics of cleft heating, insofar as they are visible to the Chatanika radar.