Non-extensive statistical analysis on solar activity dependence of magnetospheric dynamics

Abstract

Tsallis q-Gaussian distributions and associated q-statistics have been used for the last couple of decades to describe non-equilibrium dynamical systems with varying degrees of complexity. In the present study, we use Tsallis non-extensive statistical analysis for a better understanding of magnetospheric dynamics and its relationship with solar activity. The Tsallis' q-triplet, a set of indices (such as qsens, qstat and qrel) used as empirical quantifiers of non-extensivity, has been estimated for magnetospheric proxies such as auroral electrojet (AE) and disturbance storm time (Dst) indices, for a period of 1985–2007. Our results indicate that the degree of non-extensivity of AE index is quite different from that of Dst index in relation with solar activity dependence. We have seen that the values of the q-triplets calculated from Dst index are more solar activity dependent than those computed from AE index. This shows that, other than solar wind exertions, certain complex phenomena of internal origin also modulate the dynamics of geomagnetic fluctuations in the auroral region.