QUIET TIME UPPER THERMOSPHERIC WINDS OVER MILLSTONE HILL BETWEEN 1984 AND 1990

More than 60 multiday incoherent scatter radar experiments conducted at Millstone Hill, Massachusetts, between 1984 and 1990 have been analyzed to determine neutral winds along the magnetic meridian. The wind determinations from geomagnetically undisturbed periods have been sorted into seasonal, solar cycle, and local time bins, and climatological averages have been calculated and compared with complementary empirical wind model predictions (Hedin et al., 1991). The climatological wind averages have also been harmonically decomposed. Strong seasonal and solar cycle dependences characterize both the mean winds and diurnal wind amplitudes. This analysis suggests that the aurorally driven high-latitude circulation cell is important to the interpretation of variability in thermospheric circulation over Millstone Hill even during geomagnetically undisturbed periods.