An Update of the Observed Quasi-Biennial Oscillation of the Stratospheric Winds over the Tropics

A survey of the zonal wind in the stratosphere near the equator is made for the 32-year period 1953–84. The monthly mean zonal wind components have been calculated from daily observations at Canton Island, Gan, and Singapore at levels between 70 and 10 mb. A frequency distribution of the zonal wind at 30 mb has been derived from these data and a long-term mean quasi-biennial oscillation (QBO) has been constructed from the 14 complete cycles included in the period.