Collisions & Transport of Electrons in the Ionosphere

Abstract

Analytic expressions are given for the temperature dependent monoenergetic <i>(v_mln) </i>and the two averaged (<v>/<i>n</i> and v/n) collision frequencies for the electron impact with N₂, O₂, N, O, He, Ne, Ar and H in the electron temperature range 100-5000K. These expressions are based on recent experimental and reliable theoretical models of momentum transfer cross-sections for the target gases. Using the latest and reliable atmospheric and ionospheric models for the densities and temperatures of neutral and ionic gas targets, the electron collision frequency <<i>v_g</i>> has been estimated in the upper region of the ionosphere (100-500km). It is observed that at altitudes above 140km, <<i>v_g</i>> values are highest in the winter and lowest in the summer for high solar activity. However, for low solar activity, there is no such change in <<i>v_g</i>>. A study of various electron transport properties shows that their behaviour is opposite to that of <<i>v_g</i>> as expected.