The extent of Pc 1 source region in high latitudes

Abstract

The spacial extent of the source region of Pc 1 geomagnetic pulsations is investigated with respect to several such events recorded simultaneously at thirteen stations in Canada. The investigation is based on amplitude distribution obtained through reduction of the data acquired with induction magnetometers at those stations.Propagation from the source region is not isotropic but tends to align with geomagnetic latitude and longitude. The spacial gradient of amplitude near the source region becomes as large as 10 dB/100 km. Left-hand polarization does not seem to be confined to the source region. Size of source regions is discussed.