Possible Effect of Small & Large Wind Shears on Temperate Latitude Sporadic E

Abstract

The occurrence of sporadic E at temperate latitudes in the eastern zone is found to be more frequent during summer than in the western zone, but a reversal take, place during winter. Also, the frequency distribution of sporadic E shows a similar trend with some anomaly in the low frequency end of<i> f₀</i>Es and <i> f_b</i>Es. These are considered to be due to comparatively large wind shears (calculated) in the eastern zone during summer months. The reduction of wind shear during winter months in Eastern zone (as compared to the western zone) explains the reverse effect. This reduction is found to be more during low solar activity and as such, more frequent sporadic E in the western zone during winter. The anomaly which is found in the low frequency end of <i>f₀</i>Es and <i>f_b</i>Es is considered to be due to very small wind shear.