巴基斯坦近40a气温时空变化特征

Spatiotemporal Variation Characteristics of Air Temperature in Pakistan in Recent 40 Years

基于巴基斯坦不同气候区4个代表站(卡拉奇、雅各布阿巴德、奎达、德罗什)1979—2018年地面观测资料和ERA-Interim气温资料,利用一元线性回归、Mann-Kendall突变检验和Morlet小波分析,分析其气温时空变化特征。结果表明:(1)巴基斯坦过去40 a经历了先降温后增温的过程,除北部山区年平均气温增温趋势显著,四季总体都有增温,春秋两季增温趋势显著。巴基斯坦于1998年左右发生气温突变,年平均气温存在4~5、12、20~22和32 a的周期。(2)ERAInterim再分析资料与地面观测数据拟合分析显示两者相关性达到极显著水平,除北部山区外,在大部分区域误差较小,能够较好地反映巴基斯坦气温的变化特征。(3)巴基斯坦年、季平均气温空间分布地带性明显,高温区位于南部印度河平原、三角洲地区,低温区分布在北部山区,年、春季、秋季平均气温变化在空间上总体均呈现明显增长趋势.

Based on ERA-Interim air temperature data and ground observation data of 4 representative stations(Karachi,Jacobabad,Quetta,Drosh)in different climate zones in Pakistan,the characteristics of air temperature change were analyzed by using the methods of linear regression,Mann-Kendall mutation test and Morlet wavelet analysis.The results showed:(1)Pakistan experienced a process of air temperature decreasing at first and then increasing over the last 40 years.Except for the northern mountainous area,the annual mean air temperature increased significantly,and the air temperature increased in all four seasons,especially in spring and autumn.The air temperature mutation occurred around 1998,and the annual mean air temperature experienced the cycles of 4-5,12,20-22 and 32 a.(2)The fitting analysis of ERA-Interim reanalysis data and ground observation data shows that the correlation is extremely significant,and the error is small in most areas except the northern mountainous area.Hence,it could reflect the characteristics of air temperature change in Pakistan.(3)The spatial distribution of annual and seasonal mean air temperature in Pakistan shows distinct zonality.The high air temperature zone was located in the Indus Plain and delta area in the south,while the low air temperature area is located in the northern mountainous area.The annual,spring and autumn mean air temperature variation shows an obvious increasing trend in space.