Low latitude geomagnetic bays and IMF sector polarity

Abstract

From the examination of IMF data and low latitude positive bays over an interval of 13 years, it is shown that the polarity of the IMF controls seasonal variation in the occurrence of the bays. The study suggests an appreciable contrast between the frequency of bay events during passage of the 'toward' and 'away' sectors and that this feature is most prominent in summer minimum and autumnal equinoctial maximum. The differences in the frequency of occurrence of low latitude positive bays for the two sectors, as a function of local time, is found to be a feature of the equatorial region only.