Spatiotemporal precipitation variations in the arid Central Asia in the context of global warming  

作　　者：CHEN FaHu HUANG Wei JIN LiYa CHEN JianHui WANG JinSong 

机构地区：[1]MOE Key Laboratory of West China＇s Environmental System, Lanzhou University, Lanzhou 730000, China [2]Key Open Laboratory of Arid Climate Change and Disaster Reduction, China Meteorological Administration, Lanzhou 730020, China

出　　处：《Science China Earth Sciences》2011年第12期1812-1821,共10页中国科学（地球科学英文版）

基　　金：supported by National Basic Research Program of China (Grant No. 2010CB950202);National Natural Science Foundation of China (Grant Nos. 40971056 and 41021091);Fundamental Research Funds for the Central Universities (Grant No. LZUJBKY-2009-82)

摘　　要：This study analyzed the temporal precipitation variations in the arid Central Asia （ACA） and their regional differences during 1930-2009 using monthly gridded precipitation from the Climatic Research Unit （CRU）. Our results showed that the annual precipitation in this westerly circulation dominated arid region is generally increasing during the past 80 years, with an apparent increasing trend （0.7 mm/10 a） in winter. The precipitation variations in ACA also differ regionally, which can be divided into five distinct subregions （Ⅰ West Kazakhstan region, Ⅱ East Kazakhstan region, ⅢCentral Asia Plains region, Ⅳ Kyrgyzstan region, and V Iran Plateau region）. The annual precipitation falls fairly even on all seasons in the two northern subregions （regions Ⅰ and Ⅱ, approximately north of 45°N）, whereas the annual precipitation is falling mainly on winter and spring （accounting for up to 80% of the annual total precipitation） in the three southern subregions. The annual precipitation is increasing on all subregions except the southwestern ACA （subregion Ⅴ） during the past 80 years. A significant increase in precipitation appeared in subregions Ⅰ and Ⅲ. The long-term trends in annual precipitation in all subregions are determined mainly by trends in winter precipitation. Additionally, the precipitation in ACA has significant interannual variations. The 2-3-year cycle is identified in all subregions, while the 5-6-year cycle is also found in the three southern subregions. Besides the inter-annual variations, there were 3-4 episodic precipitation variations in all subregions, with the latest episodic change that started in the mid- to late 1970s. The precipitations in most of the study regions are fast increasing since the late 1970s. Overall, the responses of ACA precipitation to global warming are complicated. The variations of westerly circulation are likely the major factors that influence the precipitation variations in the study region.This study analyzed the temporal precipitation variations in the arid Central Asia (ACA) and their regional differences during 1930-2009 using monthly gridded precipitation from the Climatic Research Unit (CRU). Our results showed that the annual precipitation in this westerly circulation dominated arid region is generally increasing during the past 80 years, with an apparent increasing trend (0.7 mm/10 a) in winter. The precipitation variations in ACA also differ regionally, which can be divided into five distinct subregions (I West Kazakhstan region, II East Kazakhstan region, III Central Asia Plains region, IV Kyrgyzstan region, and V Iran Plateau region). The annual precipitation falls fairly even on all seasons in the two northern subregions (regions I and II, approximately north of 45°N), whereas the annual precipitation is falling mainly on winter and spring (accounting for up to 80% of the annual total precipitation) in the three southern subregions. The annual precipitation is increasing on all subregions except the southwestern ACA (subregion V) during the past 80 years. A significant increase in precipitation appeared in subregions I and III. The long-term trends in annual precipitation in all subregions are determined mainly by trends in winter precipitation. Additionally, the precipitation in ACA has significant interannual variations. The 2-3-year cycle is identified in all subregions, while the 5-6-year cycle is also found in the three southern subregions. Besides the inter-annual variations, there were 3-4 episodic precipitation variations in all subregions, with the latest episodic change that started in the midto late 1970s. The precipitations in most of the study regions are fast increasing since the late 1970s. Overall, the responses of ACA precipitation to global warming are complicated. The variations of westerly circulation are likely the major factors that influence the precipitation variations in the study region.

关 键 词：arid Central Asia annual and seasonal precipitation changing tendency regional difference 

分 类 号：P467[天文地球—大气科学及气象学] X16[环境科学与工程—环境科学]