Enhancement of Thomson scatter by charged aerosols in the polar mesosphere: Measurements with a 1.29‐GHz radar

The summer polar mesosphere was observed with the Sondrestrom 1.29‐GHz radar with a new high‐resolution data acquisition mode. On one occasion, a spatially narrow enhancement in the backscattered power was seen near an altitude of 88 km. We discuss possible explanations and propose that this layer may be the first example of polar mesosphere summer echoes (PMSE) detected above 1 GHz. Specifically, we suggest that these echoes are enhanced Thomson scatter from a layer of charged aerosols, and we speculate upon the size and charge state.