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Key Points We study dusk‐dawn asymmetries in 7 years of Super Dual Auroral Radar Network convection maps which are introduced by solar wind orientations, or data processing Asymmetries due to interplanetary magnetic field B y can occur in the strength and location of the convection cells, and the return flow width Asymmetries due to the background model are likely to occur in the locations of the convection cells 

Key Points We identify changes in derived convection maps when PolarDARN and StormDARN are added, and show the impact of different processing Derived convection parameters are highly susceptible to processing variables and which radars are included We show how the number of backscatter echoes per map is critical to the integrity of the maps, and discuss how this impacts map quality 

Abstract We analyzed the contribution of electromagnetic ion cyclotron (EMIC) wave driven electron loss to a flux dropout event in September 2017. The evolution of electron phase space density (PSD) through the dropout showed the formation of a radially peaked PSD profile as electrons were lost at highL*, resembling distributions created by magnetopause shadowing. By comparing 2D Fokker Planck simulations of pitch angle diffusion to the observed change in PSD, we found that theμandKof electron loss aligned with maximum scattering rates at dropout onset. We conclude that, during this dropout event, EMIC waves produced substantial electron loss. Because pitch angle diffusion occurred on closed drift paths near the last closed drift shell, no radial PSD minimum was observed. Therefore, the radial PSD gradients resembled solely magnetopause shadowing loss, even though the local pitch angle scattering produced electron losses of several orders of magnitude of the PSD.