Buonsanto This project will use Millstone Hill incoherent scatter radar data and Fabry-Perot interferometer data to study ion-neutral coupling and thermospheric dynamics. A primary goal is to perform a statistical study to derive an improved value for the O+, O collision frequency. This parameter is important in the application of radar techniques for measuring thermospheric neutral winds. Recent work at Millstone Hill has shown that horizontal gradients in the ion velocity field and vertical neutral winds are large enough to have significant effects on the winds derived from ion velocity measurements, even under quiet geomagnetic conditions. This study will quantify the effects of both horizontal ion velocity gradients and vertical neutral winds on both the derived collision frequency and the wind climatology at Millstone Hill. The new results will be used to assess the accuracy of earlier work carried out using the servo model method, including the tidal decomposition of winds over a full solar cycle.
