Electron Aurora and Polar Rain Dependencies on Solar Wind Parameters

摘要

Data analysis was performed using 17 years of Defense Meteorological Satellite Program SSJ/4/5 data to characterize the relations between the solar wind parameters and the electron low-energy fluxes measured on both magnetic poles (magnetic latitude above 55 degrees). Inputs are solar wind velocity, density, dynamic pressure, and B-z of the interplanetary magnetic field. The median of electron energy flux for each MLAT-MLT pair has been computed for given values of solar wind condition parameters. Results highlight that high velocity, density or pressure implies higher energy flux overall, higher polar rain energy fluxes, and wider nightside oval. There seems to be a positive correlation between polar rain and solar wind density, contrary to a previous study. As a function of B-z, the oval width has a "U" shape and the polar cap activity a "V" shape, with their minimum at B-z around zero.