Three dimensional distribution of HF enhanced airglow

*B. Gustavsson[1] ,T. Sergienko [2]
B. U. E. Brandstrom [2],T. Aso [1],M. T. Rietveld [3]
F. Honary [4],A. Steen [5]
National Institute of Polar Research, Tokyo,Japan[1]
Swedish Institute of Space,Kiruna Sweden[2]
Max-Planck Institut fur Aeronomie, Germany Also at EISCAT, Ramfjordmoen, Norway[3]
Department of Communication Systems, Lancaster University, Lancaster, England[4]
Remspace, Linkoping Sweden[5]

This report presents the first estimates of the three-dimensional volume emission rate of enhanced O(1D) 630 nm airglow caused by HF radio wave pumping in the ionosphere. A region of enhanced airglow was imaged by three stations in the Auroral Large Imaging System (ALIS) in northern Scandinavia. These images allowed for a tomography-like inversion of the volume emission of the airglow. The altitude of maximum emission was found to be around 235 +/- 5 km with typical horizontal and vertical scale sizes of 20 km. The altitude of maximum emission is found to be approximately 10 km below the altitude of the enhanced ion line and 15 km above the altitude of maximum electron temperature. Comparisons of the measured altitude and temporal variations of the 630 nm emission with modeled emission caused by O(1D) excitation from the high energy tail of a Maxwellian electron distribution show significant deviations.