Altitude variations of high-latitude neutral winds in the lower E region during disturbed conditions
Department of Physics & Astronomy
Clemson University
To first order, the neutral winds in the high-latitude E region during disturbed conditions can be understood as a response primarily to the Lorentz forcing associated with the two-cell plasma convection pattern in the plasma drifts. At least that is the case above ~115-km altitude where the Pedersen conductivity, and thus the Pedersen drag, is dominant. In the lower E region, however, the response is more complicated in part because the drag terms associated with the Hall conductivity become important, which leads to a change in flow direction more so than a change in flow magnitude. In addition, the flow in the lower E region is part of a three-dimensional circulation linked by mass continuity, leading to a strong vertical coupling between different levels. These effects can be difficult to discern in measurements from single events but become more evident when larger, height-resolved data sets are considered. A combination of rocket and incoherent scatter radar wind profile data sets, as well as numerical modeling results, will be used to illustrate the effects.