Occurrence probability of solar-geomagnetic-weather relations

Abstract

Relationships of the vorticity area index (VAI) and the geomagnetic activity (Ap) to solar magnetic sector boundary passage (SBP) are examined in terms of the probability of occurrence of these associations with individual SBP. The results reveal that the probability of occurrence of the characteristic variation in the VAI in relation to the SBP is comparable to the well-established association between Ap and SBP. This similarity in the occurrence probability of VAI-SBP association to that of Ap-SBP association with a value close to 60% may be considered to be adequate to dispel the doubt that sector related effects on the VAI have arisen from statistical sampling fluctuations. It is further shown that even though the occurrence probability of these associations are nearly equal, the sector related effects on VAI are completely independent of the nature of transient changes in the geomagnetic activity accompanying the SBP.