LARGE-SCALE ATMOSPHERIC CIRCULATION AND ITS INFLUENCE ON WINTER TEMPERATURE IN THE NORTHERN HEMISPHERE

The global temperature varies on a large\|scale and manifests a significant secular trend. Many researchers attribute the changes of temperature to the greenhouse warming.In this paper the attribution of large\|scale atmospheric circulation is emphasized. Some early studies paid more attention to the North Atlantic Oscillation and Northern Pacific Oscillation. However, the large\|scale atmospheric circulation plays a more important role in the northern hemispheric winter temperature variation.Index cycle is the most important monitor index to measure the basic atmospheric circulation status. The difference in zonally averaged sea level pressure (or geopotential heights) between 35°N and 55°N ( or between 40°N and 60°N) was usually used to measure the “high index” or “low index” for the northern hemisphere. In the high index state, the northern hemispheric temperature is high, and vice versa. About 27 2% annual variance of the temperature can be accounted for by the zonally western wind,the North Atlantic Oscillation and the North Pacific Oscillation in the northern hemisphere during the last 50 winters.