LONG-PERIOD WAVES IN MESOSPHERIC WINDS AT SASKATOON (52-DEGREES-N)

Long-period variations of winds observed by the radio reflection technique at Saskatoon, from 65 to 110 km, 1969-1975, show some significant différences from the CIRA 1972 model. The maximum amplitude of the annual wave below 80 km is found to be only 22 m s-1, while CIRA shows 45 m s-1 at this latitude. The semiannual wave below 75 km at Saskatoon has an amplitude only half that of CIRA. Its phase shows a consistant downward propagation from 118 to 70 km at 8 km month-1. No appréciable terannual wave was found at Saskatoon, but a weak 3-month wave shows the same phase progression pattern as for the semian-nual. A QBO is found at Saskatoon with amplitude of 10 m s-1 above 100 km. © 1979, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.