HODOGRAPH ANALYSIS OF MESOPAUSE REGION WINDS OBSERVED BY 3 MF RADARS IN THE CANADIAN PRAIRIES

A new method of hodograph analysis is introduced and applied to studie s of long period wind oscillations (2 to 10-hour period) in the upper mesosphere, observed by a triangle of medium frequency radars (500 km spacing) in the Canadian Prairies. This is compared with a method of s patial Fourier analysis which is also employed to study these oscillat ions. The results of these analyses are shown to be consistent with th e behavior of atmospheric gravity waves: in particular, the gravity wa ve propagation directions are found to vary with season and with latit ude. However, the directions do not seem to be consistent with blockin g by the mean wind field, probably due to the gravity waves having pha se velocities much higher than typical mean winds.