Periodic variations in stratospheric meridional wind from 20 to 65 km - 80 N to 70 S

Long-term periodic features in the meridional wind between 20 and 65 km attitude are analyzed. No appreciable periodic waves are found in the tropics. The quasi-biennial oscillation, annual wave, and four-month wave have maximum amplitudes of about 10, 20, and 10 m/s respectively in the arctic near 45 km. The phase of the annual wave changes by nearly 180 deg in a narrow zone near 45 deg N. The semiannual wave has an amplitude of 10 m/s near 50 deg N above 50 km with equinoctial phase dates in the region of maximum amplitude. The location of this polar semiannual wave corresponds closely to that previously found in the zonal wind.