The Southern Oscillation in the Stratosphere

Abstract The signal of the Southern Oscillation in the lower half of the Northern Hemisphere stratosphere in winter appears to be as follows: In the extreme of the Southern Oscillation when the trade winds are comparatively weak in the South Pacific Ocean, stratospheric geopotential heights and temperatures tend to be higher over the Arctic and lower in middle latitudes than in the opposite extreme. At the same time, the polar-night stratospheric jetstream tends to be weaker and the subtropical westerlies to be stronger. The conclusions are based on 11 extremes within a 15-year period and on data at standard pressure levels as high as 10 mb.