Observations and Modeling of Enhanced Ion Temperatures in the Polar Cap Ionosphere

Abstract:

We examine ion temperature enhancements observed with the Resolute Bay Incoherent Scatter Radar North. Enhanced ion temperatures most frequency occur under IMF Bz northwards conditions in the noon sector. This is possibly due to lobe reconnection driving sunwards plasma convection in the dayside ionosphere, which may be connected to higher instances of ion heating. We use the Ionosphere/Polar Wind Model driven by realistic global convection and precipitation patterns to attempt to replicate several significant ion temperature enhancements observed on the dayside. While the model produces small temperature enhancements in some cases, it could not match the magnitude of the observed ion temperatures, or their duration. We hypothesis that small- and mesoscale structures that are not currently included in the model drivers may be significant for ion heating in the polar cap ionosphere.