1955～2015年汉中极端气温事件变化特征

Changes of Extreme Temperature Events in Hanzhong during 1955～2015

基于汉中1955~2015年逐日最高气温和最低气温实测数据,利用RClimDex软件计算了11项极端气温指数,运用线性拟合、Mann-Kendall法分析了汉中极端气温事件变化趋势和突变特征。结果表明:(1)近60年汉中增温趋势明显,极端最高气温、最低气温分别以0.06℃/10a、0.45℃/10a趋势增加;(2)夏日日数、热夜日数、暖日日数、暖夜日数、作物生长期分别以2.91d/10a、3.31d/10a、0.67d/10a、2.66d/10a、3.89d/10a的趋势增加;(3)霜冻日数、冷日日数、冷夜日数和气温日较差分别以-4.41d/10a、-0.57d/10a、-1.93d/10a、-0.15℃/10a的趋势减少;(4)汉中各极端气温指数突变年不一,主要集中在20世纪60至70年代、20世纪90年代至21世纪初叶。

Based on the daily maximum and minimum temperature of Hanzhong meteorological station from 1955~2015,eleven indices of extreme temperature were calculated by using RClimDex.The change trend and mutation characteristics of eleven indices of extreme temperature were analyzed by the linear regression and Mann-Kendall.The results showed that the temperature increment was obvious in Hanzhong during 1955~2015,with extreme maximum temperature and minimum temperature increasing at rates of 0.06 ℃/10 a and 0.45 ℃/10 a.The occurrence of summer days,tropical nights,warm days,warm nights and growing season length duration had increased by 2.91,3.31,0.67,2.66 and 3.89 d/10 a,while the frequency of frost days,cool nights,cool days and diurnal temperature range showed decreasing trends at rates of -4.41,-0.57,-1.93 d/10 a and -0.15 ℃/10 a.The change years of the extreme temperature indices were different in Hanzhong,mainly from the 1960s to the 1970s and from the 1990s to the early 21st century.