LASP Magnetosphere Seminars

Abstract

Ionospheric Pedersen and Hall conductances play a critical role in magnetosphere-ionosphere-thermosphere coupling. Existing parameterizations commonly estimate conductances from the energy flux and average energy of precipitating electrons. However, most were developed under limited conditions and without considering the effect of the background geomagnetic field, resulting in considerable uncertainties and errors in their applications. In this talk, I will revisit the calculation of electron-precipitation-induced conductances. We perform systematic calculations under diverse background scenarios, considering variations in geographic location, solar and geomagnetic activity, local time, and season, for a total of nearly two million cases. We find that geomagnetic field strength is a critical factor. Even under identical electron precipitation, variations in the magnetic field can produce several-fold differences in conductance. Motivated by this finding, we develop a new fast parameterization for Maxwellian electron precipitation with average energies of 1–20 keV that incorporates magnetic-field dependence, with fitting errors within ±5%. I will also discuss how the spectral shape of electron precipitation, beyond energy flux and average energy, can significantly affect ionospheric conductance.