1981—2019年西北干旱区暖湿化分析

Analysis of Warming and Humidification in the Arid Region of Northwest China During 1981-2019

[目的]探究我国西北干旱区20世纪80年代以来的暖湿气候变化情况。[方法]利用国家气象数据中心发布的1981—2019年0.5°×0.5°气温和降水量月值格点资料,采用线性倾向率、Mann-Kendall检验、累积距平法,对近39年来该地区气温和降水时空演变特征进行研究。[结果]近39年来西北干旱区平均气温呈现显著上升趋势,气温倾向率为0.377℃/10 a(P<0.01),天山亚区增温趋势最大;各季节平均气温均呈显著增高趋势,春季增温趋势最大,冬季增温趋势最小,气温倾向率仅为0.121℃/10 a(P>0.05);年平均气温在1997年发生增温突变,进入21世纪增温趋势减缓。西北干旱区年降水量整体呈增加趋势,降水量倾向率为9.509 mm/10a(P<0.01),天山亚区增湿趋势最大,降水量倾向率为25.673 mm/10 a(P<0.01);四季均呈降水量增加趋势,夏季增加趋势最大,冬季降水量增加趋势相对较小;年降水量在2001年发生突变,降水量增加趋势明显。[结论]西北干旱区整体处于暖湿阶段,尤其天山亚区暖湿化最显著。

[Objective]To explore the changes of warming and humidification climate in the arid areas of northwest China since 1980s.[Method]Using the monthly temperature and precipitation from a 0.5°×0.5°gridded datasets during 1981-2019 released by the National Meteorological Information Center,the spatiotemporal evolution characteristics of temperature and precipitation in the region over the past 39 years were studied using linear propensity rate,Mann-Kendall test and cumulative anomaly method.[Result]The temperature in the arid region of northwest had been increasing at a rate of 0.377℃/10 a(P<0.01)over the past 39 years,with the largest warming trend in the Tianshan subregion.The average temperature of all seasons showed a significant increasing trend,with the largest warming trend in spring.The warming trend in winter was the smallest,with a rate of only 0.121℃/10 a(P>0.05).The mean annual temperature had an abrupt change in 1997,and the warming trend slowed down in the 21st century.The annual precipitation in the northwest arid region showed an increasing trend with a rate of 9.509 mm/10a(P<0.01),and the Tianshan subregion showed the largest increasing trend with 25.673 mm/10a(P<0.01).The precipitation trend increased in all seasons,with the greatest increase in summer and relatively small increase in winter;the annual precipitation had an abrupt change in 2001,followed by a significant trend of increasing precipitation.[Conclusion]The arid region of northwest China is in the warm and humid stage,especially in the Tianshan subregion.