© European Geosciences Union 2004
Longitudinal and latitudinal variations in dynamic characteristics of the MLT (70−95km): a study involving the CUJO network
1Institute of Space and Atmospheric Studies, University of Saskatchewan, 116 Science Place, Saskatoon, SK, S7N 5E2, Canada
2CIRES, University of Colorado, Boulder, USA
3Department of Electrical and Computer Engineering, University of Alaska, Fairbanks, USA
4Department of Physics and Astronomy, University of Western Ontario, London, Canada
5Communications Research Laboratory, Tokyo, Japan
Abstract. The newly-installed MFR (medium frequency radar) at Platteville (40°N, 105°W) has provided the opportunity and impetus to create an operational network of middle- latitude MFRs stretching from 81°W–142°E. CUJO (Canada U.S. Japan Opportunity) comprises systems at London (43°N, 81°W), Platteville (40°N, 105°W), Saskatoon (52°N, 107°W), Wakkanai (45°N, 142°E) and Yamagawa (31°N, 131°E). It offers a significant 7000km longitudinal sector in the North American-Pacific region, and a useful range of latitudes (12–14°) at two longitudes.
Annual climatologies involving both height and frequency versus time
contour plots for periods from 8h to 30 days, show that the changes with longitude are very
significant and distinctive, often exceeding the local latitudinal variations. Comparisons
with models and the recent UARS-HRDI global analysis of tides are discussed. The fits
of the horizontal wave numbers of the longer period oscillations are provided in unique
frequency versus time contour plots and shown to be consistent with the expected
dominant modes. Annual climatologies of planetary waves (16 day, 2 day) and gravity waves
reveal strong seasonal and longitudinal variations.