The Incorporation of Ice Station Data into a Study of Recent Arctic Temperature Fluctuations

Abstract

High-latitude monthly surface temperature data for the years 1954?75 are objectively analyzed. All existing monthly temperatures from drifting ice stations are included in the analyses. The variances about the monthly means are found to be no larger in the central Arctic than in the northern land areas. Surface temperature trends computed by linear regression vary considerably by season and by geographical region within the Arctic. The spatial distribution of the recent temperature trends is interpreted in terms of the empirical orthogonal functions accounting for the largest fractions of the temperature variance. The net area-weighted 22-year trend for the region north of 60°N is ?0.02°C year?1 but this relatively small value is found to be the resultant of cooling prior to the.mid-1960's and warming thereafter. During both the cooling and warming periods, the trends are found to be largest in the 70?80°N latitude belt. Inferences about the significance of the results are made by comparing the computed trends with those excepted when the temperatures are randomly distributed about their monthly means.