Changing trends and abrupt features of extreme temperature in mainland China during 1960 to 2010

Abstract. A few researches based on the 10th (90th) percentiles as thresholds had presented to assess moderate extremes in China. However, there has been very little research reported on the occurrences of high extremes warm days (TX95p and TX99p) and cold nights (TN05p and TN01p) according to 95th or 99th (5th or 1st) percentiles which has more directly impacts on society and ecosystem systems. The study showed: (1) the frequencies of TX95p and TX99p averagely increased by 1.80 days/10 a and 0.62 days/10 a respectively in all stations of mainland China, and TX95p in 50.42 % and TX99p in 58.21 % of the stations increased significantly, but TN05p in 83.76 % and TN01p in 76.48 % of stations decreased significantly, and the frequencies of TN05p and TN01p averagely decreased by 3.18 days/10 a and 1.01 days/10 a respectively in all stations, (2) except in Central China, other regions of China showed an increasing trend in TX95p and TX99p, but vast majority of the mainland China showed a decreasing trend in TN5p and TN01p; and (3) the trends of TX95p and TX99p mutations time were in about 1990s or 2000s, but the trends of TN05p and TN01p has mutated in the late 1970s and early 1980s. After the mutation, the increasing trend of warm day and hot day is greater than before in most regions which indicated that more potential risk of heatwaves in future, but the decreasing trend of cold day and frozen day is not enlarge than before.