Short-Term Climatic Variability of the Arctic

Abstract

The circulation of the Arctic atmosphere undergoes large fluctuations about its monthly and annual means. The statistics of Arctic sea level pressure and temperature are evaluated in order to place Arctic atmospheric variability into the context of fluctuations elsewhere. The persistence of monthly sea level pressure anomalies in the Arctic is smaller than in the subtropics but greater than in middle latitudes. This persistence is strongest in winter. Air temperature anomalies are less persistent in the Arctic than in lower latitudes, except during the autumn freeze-up season. Monthly Arctic pressure anomalies show a relatively strong association with concurrent anomalies in the North Atlantic, especially during the winter half of the year. Associations with North Pacific anomalies are weak. During the past twenty years, the greatest warming has occurred over Alaska, the North Atlantic marginal ice zone, and north central Asia. Cooling has occurred over much of Europe, especially Scandinavia. The COADS sea surface temperature changes support the pattern of temperature change derived from land station data. The pattern of recent high-latitude temperature change is consistent with and at least partially attributable to corresponding changes in the sea level pressure (gradient wind) field.