Neutral winds in the polar thermosphere as measured from Dynamics Explorer

Remote sensing measurements of the meridional thermospheric winds using the Fabry‐Perot interferometer on Dynamics Explorer have been combined with the in situ measurements of the zonal component using the Wind and Temperature Spectrometer on the same spacecraft. The two data sets, with appropriate phasing and averaging, determine the vector wind along the track of the polar orbiting spacecraft. The technique enables a direct experimental description of the global thermospheric wind field to be made. Data from both summer and winter poles are shown to illustrate the dominant effect of momentum transfer between the neutrals and the convecting ions in setting up the neutral circulation for quiet geomagnetic conditions (winter pole) and relatively active conditions (summer pole).