基于ETCCDI指数2017年中国极端温度和降水特征分析

利用中国1961—2017年2419站均一化逐日气候数据,计算了气候变化检测和指数联合专家组定义的26个极端气候指数,分析2017年中国极端温度和降水特征。结果表明：2017年中国区域平均的所有极端高温指数均高于1961—1990年30年平均,所有极端低温指数均低于1961—1990年30年平均。中国区域平均的多个极端温度指数达到或者接近历史极值,其中年最小日最高气温(TXn)和年最小日最低气温(TNn)均达到历史最高值,冷夜(TN10p)、冷昼(TX10p)和持续冷日日数(CSDI)达到历史最低值。年最大日最高气温(TXx)、年最大日最低气温(TNx)、暖夜(TN90p)、霜冻(FD)、冰冻(ID)、热夜(TR)、生长期长度(GSL)排在1961年以来的第2或第3位,其余极端温度指数全部排在了1961年以来前10位。2017年中国区域平均的10个极端降水指数中,有7个指数值处于1961—2017年1个标准差范围内,指示2017年的极端降水接近正常年。

Characteristics of extreme temperature and precipitation in China in 2017 based on ETCCDI indices

Based on the homogenized daily data in 2419 stations in China from 1961 to 2017, we calculated 26 extreme temperature and precipitation indices as defined by the Expert Team on Climate Change Detection and Indices (ETCCDI), and analyzed the characteristics of extreme temperature and precipitation in China in 2017. For China average, all the high temperature indices in 2017 were above the 30-year average of 1961—1990 and the extreme low temperature indices were lower than their corresponding 1961—1990 average. The annual minima of daily maximum temperature (TXn) and daily minimum temperature (TNn) reached the highest recorded value, while the number of cold nights (TN10p), cold days (TX10p), and cold spell duration index (CSDI) reached the lowest recorded value. Some indices were ranked at the second or third place since 1961, including annual maxima of daily maximum temperature (TXx) and daily minimum temperature (TNx), warm nights (TN90p), frost days (FD), icing days (ID), tropical nights (TR), and growing season length (GSL). Other extreme temperature indices were ranked in the top 10 since 1961. Meanwhile, 7 out of 10 extreme precipitation indices averaged over China in 2017 were within the range of one standard deviation of precipitation indices during 1961-2017, indicating a normal situation for extreme precipitation in 2017.