Initial ionospheric observations made by the new Resolute incoherent scatter radar and comparison to solar wind IMF

Abstract

The first Resolute incoherent scatter radar observations of the polar ionospheric F region show the fine control of the ionospheric plasma density and flow (electric field) by the solar wind interplanetary magnetic field (IMF). A summary of 8 days of observations is presented and 10 IMF B z southward turning events during this period are analyzed in terms of the time delay of plasma density enhancements and ionospheric convection intensification with respect to the timing of B z southward turning. We find that N e enhancements are strongly tied to strong (≳5 nT) IMF B z southward turnings; arrive 25-75 mins (depending on MLT) after the IMF pulse arrives at the bowshock nose; last as long as B z stays southward; contain as small as ∼25 km horizontal substructures; are altitudinally smooth, a characteristic of a solar produced plasma. The most predictable response of ionospheric convection is anti-sunward flow intensification on average ∼25 mins after B z southward change. © 2010 by the American Geophysical Union.