Regional Difference of Climate Trend and Abrupt Climate Change in China during 1961—2006

Based on observed meteorological data,modified FAO56 Penman-Monteith model,methods of linear trend,Mann-Kendall nonparametric and moving T-test,the trend and abrupt change of temperature and moisture conditions in China were analyzed during the period 1961-2006.Results indicated that in China as a whole,the average temperature had significant warming trends,precipitation had slightly decreasing trend,and potential evapotranspiration and aridity index had significant decreasing trends.The abrupt change of temperature occurred significantly in the late 1980s in China as a whole,moreover,it occurred earlier in Northeast China and later in South China.Precipitation had significant decreasing trend in warm temperate zone and increasing trend in West China.There had no tested significant abrupt change of precipitation in China as a whole.However,the abrupt change of precipitation occurred only in the Northwest arid region in the mid 1980s.The abrupt change of potential evapotranspiration occurred in the early 1980s in China as a whole with regional difference of earlier in East China.As for regional difference,aridity index had significant decreasing trends in the subtropical region,the Tibetan Plateau alpine region and the Northwest arid region.Moreover,aridity index had significant abrupt change in the late 1970s in China as whole,and especially in the Northwest arid region with distinctive enhancing humidity in 1986.