Geomagnetic activity and the reception of whistlers in polar regions

A correlation between the occurrence of whistlers and geomagnetic activity has often been sought. Usually the whistler data from middle-latitude stations have been used, and the results been inconclusive or even conflicting. This may be attributed at least partly to the use of the ‘whistler rate’ (the number of whistlers heard per unit time) as a suitable characteristic for comparison with geomagnetic activity indices. The whistler rate is, however, likely to be strongly dependent on the prevailing meteorological conditions; a large whistler rate may arise because a rapid succession of lightning flashes occurs in a suitable geographical area.