Multistation measurements of Pc5 geomagnetic power amplitudes at high latitudes

Geomagnetic data from four Antarctic stations, located at -80 corrected geo magnetic (CGM) latitude, have been analyzed. The magnetic local time (MLT) occurrence distributions and seasonal dependence of geomagnetic power level s in the Pc5 frequency band are studied. It is found that the pulsation pow er can be significantly influenced by the MLT location of the station at th e specific UT time considered, regardless of interplanetary conditions or g eomagnetic activity. A shift of power amplitudes toward higher values is fo und during local summer, likely in association with the increased ionospher ic conductance. The local dayside summer increase of power relative to the winter condition is higher than on the nightside. This finding is explained by the magnetospheric cusp influence on the production of geomagnetic powe r.