Hemispheric Asymmetry of Ionospheric Poynting Flux During Geomagnetically Quiet Periods

Using a large database containing DMSP F13 observations under geomagnetically quiet conditions from 1998 to 2009, the hemispheric asymmetries of the distribution of the Poynting flux were investigated. Significant hemispheric asymmetries were observed in both altitude-adjusted corrected geomagnetic (AACGM) and geographic coordinates, and the maximum average flux in the northern hemisphere was greater than that in the southern hemisphere by a factor of three in both coordinates. The distribution of downward Poynting flux hot-spot (DPFH) between the two hemispheres had longitudinal difference of ∼180°. The Poynting flux's hemispheric asymmetry in AACGM and geographical coordinates at different seasons were investigated. The observed seasonal variations in the Southern Hemisphere (SH) are not as significant as those in the Northern Hemisphere (NH). In addition, the downward net Poynting flux observed during the solstice period is greater than that observed for the equinox period above 60°S.