Physics Department Seminar University of Alaska Fairbanks

J O U R N A L    C L U B


Altitude variations of high-latitude neutral winds in the lower E region during disturbed conditions

M. F. Larsen
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.


Friday, 16 November 2018

Globe Room, Elvey Building