Publication Date:
2013-11-06
Description:
[1] Nonmigrating diurnal tides between 90–270 km are inferred from Upper Atmosphere Research Satellite (UARS) wind imaging interferometer (WINDII) winds. This study represents the first known effort to directly analyze tidal wavenumber structure and propagation direction in winds observed over this altitude range. Prominent diurnal tides include an eastward-propagating wavenumber 3, a zonally symmetric tide, and a westward-propagating wavenumber 2. UARS high resolution Doppler imager (HRDI) winds between 60 and 100 km were analyzed identically, and show excellent consistency with WINDII tides. Observed tides were compared with tidal fits to Hough Mode Extensions. WINDII tides are generally damped more slowly above 120 km than fitted tides, and the zonally symmetric tide indicates a thermospheric source not captured by Hough Mode Extensions. Our study provides additional confirmation that tides act as direct coupling agents between the troposphere and the thermosphere (and F-region), in addition to their role in the E-region dynamo.
Print ISSN:
0148-0227
Topics:
Geosciences
,
Physics
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