ectron Aurora and polar rain dependencies on Solar Wind Drivers

Data analysis was performed using 17 years of DMSP SSJ/4/5 data to characterize the relations between the solar wind drivers and the electron low-energy fluxes measured on both magnetic poles (magnetic latitude above 55°). Inputs are solar wind velocity, density, dynamic pressure and Bz of the interplanetary magnetic field. Median of electron energy flux for each MLAT-MLT pair have been computed for given values of solar wind drivers. 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 as opposed to what Riehl & Hardy (1986) found. As a function of Bz, the oval width as a “U” shape and the polar cap activity a “V” shape, with their minimum at Bz around zero. 

Riehl, K. B., & Hardy, D. A. (1986). Average characteristics of the polar rain and their relationship to the solar wind and the interplanetary magnetic field. Journal of Geophysical Research: Space Physics, 91 (A2), 1557-1571. Retrieved from https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/JA091iA02p01557 doi: https://doi.org/10.1029/JA091iA02p01557