Comparison of geostrophic and observed winds in the upper mesosphere over Saskatoon, Canada
Abstract
Thicknesses derived from the Stratospheric and Mesospheric Sounder on Nimbus 7 and 30-mbar height analyses based on radiosondes have been combined to give monthly mean height charts of the upper mesosphere, (0.01-mbar level, approximately 78-80 km). Four years of data are available, 1979-1982. Based on this material, the geostrophic winds were derived for the grid point 50 deg N, 110 deg W and compared with winds observed over Canada (52 deg N, 107 deg W) using the Saskatoon medium frequency radar. Agreement, especially in the summer months, was very good; however, significant ageostrophy was evident in autumnal and winter months. Possible causes are confluence associated with large-scale circulations and gravity-wave drag.
- Publication:
-
Journal of Atmospheric and Terrestrial Physics
- Pub Date:
- October 1987
- DOI:
- 10.1016/0021-9169(87)90105-X
- Bibcode:
- 1987JATP...49..987L
- Keywords:
-
- Atmospheric Circulation;
- Geostrophic Wind;
- Mesosphere;
- Winds Aloft;
- Autumn;
- Height;
- Radar Measurement;
- Saskatchewan;
- Winter