The results from the two runs of LLIONS are used to calculate
the linear, field-line-integrated Rayleigh-Taylor grow rates.
Run #1 with no significant cross equator neutral wind has a
symmetric ionosphere distribution about the dip equator.
Run #2 was asymmetric, but it also had significantly less
plasma. The northward neutral wind was constant for 4 hours
before sunset as well as after sunset. This caused plasma
in the northern hemisphere to be pressed down into the
chemically dominated altitudes. This effectively reduced the
plasma in the F region.
The field-line-integrated O+ density is plotted for each case
along with the growth rate magnitudes.
The second run has a higher ionosphere but reduced integrated plasma density.
The GxB driven Rayleigh-Taylor instability is greatly reduced by the cross equator wind but only if the wind has been active for a 'long' time before sunset. Note that the ExB drift instability has not been reduced by the cross equator wind. Potentially, bottomside spread F may still occur even if the topside plasma plumes are suppressed by the cross equator wind.
