Seasonal Variation of Surface Temperature Change during the Last Several Decades

Using the historical surface temperature dataset compiled by Climatic Research Unit of the University of East Anglia and the Hadley Centre of the United Kingdom, this study examines the seasonal and latitudinal profile of the surface temperature change observed during the last several decades. It reveals that the recent change in zonal-mean surface air temperature is positive at practically all latitudes. In the Northern Hemisphere, the warming increases with increasing latitude and is large in the Arctic Ocean during much of the year except in summer, when it is small. At the Antarctic coast and in the northern part of the circumpolar ocean (near 55 degrees S), where limited data are available, the changes appear to be small during most seasons, though the warming is notable at the coast in winter. However, this warming is much less than the warming over the Arctic Ocean. The seasonal variation of the surface temperature change appears to be broadly consistent with the result from a global warming experiment that was conducted some time ago using a coupled atmosphere-ocean-land model.