TROPOSPHERIC TEMPERATURE TRENDS IN THE ARCTIC - 1958-1986

Arctic temperature trends in four tropospheric layers during the period 1958-1986 are examined through analysis of a comprehensive archive of Arctic upper air meteorological data. The goals of the study are to describe the trends in Arctic tropospheric temperatures and to provide verification data for model simulations of Arctic and global climate. This analysis extends the work of previous researchers by examining rawinsonde time series from a much denser distribution of stations than was previously available and by resolving the vertical distribution of tropospheric temperatures as well. Absolute trends of 3-degrees-C/30yr or larger were found, with both cooling and warming tendencies observed in all layers. The majority of the trends, however, are not statistically significant. Considerable regional and seasonal variability is observed. Trends at many stations in Eurasia and Greenland are highly sensitive to large positive anomalies during the period 1958-1963, which may be artifacts of the data. On the basis of our analysis, we conclude that greenhouse-induced warming is not detectable in the Arctic troposphere for the 1958-1986 period.