Nighttime thermospheric winds at high latitudes

摘要: Nighttime thermospheric winds have been measured from Ester Dome, near College, Alaska (64.8°N, 147.8°W), using the high-resolution Fabry-Perot interferometer of University Michigan Airglow Observatory. The are determined Doppler shifts (0I) 15867 K (6300 A) line emission. Measurements obtained during geomagnetic quiet times in January and February 1972 averaged to obtain characteristic nighttime behavior both zonal meridional neutral wind components at F-region heights. Ion drifts this period were by Chatanika incoherent scatter radar facility. measurements average ion drift used with a three-dimensional dynamic model thermosphere determine effectiveness various forces controlling heights high-latitude thermosphere. A least squares fit calculated variations winds, drag measurements, gives Fourier coefficients latitudinal longitudinal pressure gradients that necessary drive observed pattern. results show force is essentially balanced direction. However, direction does not balance force. gradients, derived terms exospheric temperature variations, different variation predicted MSIS for latitude. westward early evening hours, opposite uses semiempirical drag.