Statistics of 1‐m wavelength plasma irregularities and convection in the auroral E Region

Data from the Sweden and Britain Radar Auroral Experiment have been utilized in a statistical study of auroral backscatter due to 1-m-scale plasma irregularities and of plasma convection in the auroral E layer. An examination of approximately 15,000 hours of backscatter amplitude data indicates that (1) the strongest backscatter is invariably associated with the main electrojets, between 1300-1900 UT and 2300-0300 UT, (2) only weak backscatter occurs in the vicinity of the convection reversals, particularly in the morning sector, and (3) the backscatter intensity can exhibit an aspect angle attenuation of between 0 and 10 dB/deg depending on the absolute intensity measured. Average convection patterns obtained from approximately 1400 hours of two-station measurements reveal a well-defined two-cell structure for all magnetic conditions. As magnetic activity increases the Harang discontinuity moves toward earlier local times, the flow speed increases and the morning convection cell expands relative to the evening cell. 32 references.

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