Climatic warming in the Tibetan Plateau during recent decades

Adequate knowledge of climatic change over the Tibetan Plateau (TP) with an average elevation of more than 4000 m above sea level (a.s.1.) has been in sufficient for a long time owing to the lack of sufficient observational da ta. In the present study, monthly surface air temperature data were collect ed from almost every meteorological station on the TP since their establish ment. There are 97 stations located above 2000 m a.s.1. on the TP; the long est records at five stations began before the 1930s, but most records date from the mid-1950s. Analyses of the temperature series show that the main p ortion of the TP has experienced statistically significant warming since th e mid-1950s, especially in winter, but the recent warming in the central an d eastern TP did not reach the level of the 1940s warm period until the lat e 1990s. Compared with the Northern Hemisphere and the global average, the warming of the TP occurred early. The linear rates of temperature increase over the TP during the period 1955-1996 are about 0.16 degreesC/decade for the annual mean and 0.32 degreesC/decade for the winter mean, which exceed those for the Northern Hemisphere and the same latitudinal zone in the same period. Furthermore, there is also a tendency for the warming trend to inc rease with the elevation in the TP and its surrounding areas. This suggests that the TP is one of the most sensitive areas to respond to global climat e change. Copyright (C) 2000 Royal Meteorological Society.