Comparison of quasi-biennial oscillations of stratospheric winds and atmospheric temperatures at different altitudes

Abstract

During 1959-89, the 12-month running means of 50 hPa zonal winds, the average atmospheric temperatures in the northern and southern hemisphere at four altitude slabs (950 hPa, 850- 300 hPa, 300-100 hPa and 100-50 hPa), Pacific and Atlantic sea surface temperature (SST) and-30hPa temperatures at North Pole and average for (10°-90° N), all showed quasi-biennial oscillations (QBO). However, whereas the wind QBO had an average spacing of 29 months, only temperatures at 300-100 hPa and Atlantic SST had similar average spacing. Other temperatures as also SO index (represented by Tahiti minus Darwin atmospheric pressure) had larger average spacing. Spectral analysis showed that whereas wind QBO had only one prominent peak at T=2.33 years, other parameters had weak QBOs near T=2.5-2.6 years except Pacific SST and 30 hPa North Pole temperature which had small peaks near T=2.3 years. All the temperatures had prominent peaks in the 3-6 year region which matched with similar peaks in the SO index. There is some indication that stratospheric wind QBO had some relation with parameters at all altitudes in tropics and with North Pole, while ENSO had considerable influence at other latitudes/altitudes.