Polarization of geomagnetic sudden commencements observed by geostationary satellites

Using magnetic data from GOES 2 and 3 geostationary satellites for the interval from August 1978 to August 1980, local time dependence of polarization of geomagnetic sudden commencements (SC's) was statistically analyzed. The polarization in the plane perpendicular to the geomagnetic field is counter clockwise on the morning side and clockwise on the afternoon side, when viewed along the field direction. This is consistent with the statistical results from ground-based magnetic data by Wilson and Sugiura (1961). A latitudinal reversal of the polarization of SC observed on the ground does not seem to occur at geostationary orbit.