SuperDARN cross polar cap potential dependence on the solar wind conditions and comparisons with models

Abstract

In this study SuperDARN Cross Polar Cap Potentials (CPCPs), collected over the year 2000, are investigated with a goal to statistically assess its relationship with various parameters of the solar wind and Interplanetary Magnetic Field (IMF). We show that SuperDARN CPCPs tend to cluster around discrete values, prescribed by the statistical model, unless the amount of points on each convection map is above ∼300. By selecting CPCP data obtained with radar coverage of >300 points, we investigate the CPCP relationship with IMF Bz and By, IMF clock angle, solar wind speed and dynamic pressure, Alfven velocity, Alfven–Mach number, and interplanetary electric field. Some reported tendencies, such as dependence upon IMF Bz, were found to be consistent with measurements by other instruments. We demonstrate that SuperDARN CPCPs show consistency with several theories/empirical models (predicting the CPCP) in terms of a linear trend but, on average, the slopes of the dependencies are at least two times smaller. We also determine the coupling function, out of those published in literature, best correlating with SuperDARN CPCPs.