Latitude dependence of the quasi‐biennial oscillation and quasi‐triennial oscillation characteristics of total ozone measured by TOMS

The 12‐month moving averages of total ozone mapping spectrometer (TOMS) total ozone data for 14 years (1979–1992) were examined for quasi‐biennial oscillation (QBO) and quasi‐triennial oscillation (QTO) and compared with stratospheric low‐latitude zonal wind and equatorial eastern Pacific sea surface temperature (SST). The equatorial ozone had a strong QBO with a period of ∼30 months, and its maxima tallied with westerly wind maxima. At other latitudes the ozone maxima spacings were often different from 30 months, more so in the northern hemisphere. A spectral analysis showed that both hemispheres had one peak at ∼20 months and another peak at ∼30 months, only up to ∼50° latitude. At higher latitudes these peaks shifted to ∼23 and ∼36 months. For 0°–50° the ∼30‐month periodicity in the northern hemisphere showed abrupt phase changes, while the southern latitudes showed a roughly gradual phase shift. The northern hemisphere had an additional periodicity at ∼4 years, roughly matching the SST. Analysis of the same data without 12‐month averaging showed the above characteristics more clearly and revealed additional peaks at ∼0.7 years (8–9 months) and ∼1.30 years (16–17 months). All of these peaks showed shifts (mostly increases) at higher latitudes.