Pedersen ionic contribution in different time scales

Abstract

Pedersen conductivity is one of the main parameters in atmospheric electrodynamics, magnetosphere-ionosphere-thermosphere coupling, and several other geophysical processes. It is determined by the collision frequency between charged and neutral components and the Earth´s magnetic field intensity through the gyrofrequency. This work analyzes the contribution of different ionic species to the variability of Pedersen conductance in time scales from hours to years within the period 1964?2008 based on the results of various atmospheric and ionospheric models. The main results are (1) there is a positive correlation between O+ density and Pedersen conductance, (2) Pedersen conductance of F layer has a larger increase with the solar activity than that of E layer, (3) Pedersen conductance has a long-term trend that is determined by Earth´s magnetic field intensity and electron density, and (4) at midlatitudes trends are mainly governed by the Earth´s magnetic field and modulated by the electron density, while at high latitudes both are important.