A Model of Median Auroral Electron Flux Deduced from Hardy 2008 Model Probability Density Maps

Abstract : The Hardy auroral precipitation flux model has been extensively used for modeling high latitude phenomena and space weather operation since its initial development in 1985. The original Hardy model (referred here as H-85 model) specifies the average pattern of auroral electron precipitation as a function of geomagnetic latitude, magnetic local time and magnetic activity Kp index. The H-85 model has recently been extended into a probability model in 2008 with a much larger collection of new DMSP observations since 1985. The upgraded Hardy model, referred here as H-08, turns out to be a large database and lacks functional representation. The purpose of this paper is to present an approach to functionally represent the H-08 model. We reduced median auroral fluxes from the H-08 model probability maps, and conducted a regression analysis to fit the median auroral fluxes using real spherical harmonics. We derived a reduced model of median auroral fluxes named as H-08MV to distinguish it from the earlier models. The developed functional representation will greatly enhance usefulness of the new Hardy model for space weather prediction.