Thermal Ion Drifts in the Dayside High-Latitude Ionosphere

Abstract

Observations of the ionospheric flow at high latitudes include not only the response of the plasma to imposed electric fields but also the response due to temporal variations in the configuration of the convection pattern. These two factors combine in different ways depending on the nature of the polar cap boundary and several interpretive problems result. Here we illustrate these problems utilizing the presently available models of ionospheric convection and different sources of data. A time variability in the ionospheric convection pattern is an essential element to be included in data interpretation but the nature of the time variation is not uniquely exposed in presently available data. The deficiencies in data interpretation are discussed together with properties of the data that may help to resolve some of the problems.