全球变暖背景下春季Hadley环流与东亚夏季风环流年际对应关系的多模式预估  

Multi-model projection of the interannual relationship between spring Hadley circulation and East Asian summer circulation under global warming

作　　者：周波涛[1,2] 

机构地区：[1]国家气候中心,北京100081 [2]中国科学院大气物理研究所竺可桢-南森国际研究中心,北京100029

出　　处：《地球物理学报》2012年第11期3517-3526,共10页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40805029;41275078);国家重点基础研究发展计划项目(2009CB421407);公益性行业(气象)科研专项(GYHY200906018)资助

摘　　要：观测事实揭示,春季Hadley环流在年际时间尺度上与东亚夏季风环流和降水具有密切联系.在未来全球变暖背景下,春季Hadley环流与东亚夏季风环流和降水的这种年际关系是否会发生变化?针对该问题,本文在评估的基础上选取五个气候模式,分析了A1B排放情景下春季北半球Hadley环流年际变率的未来变化及其与东亚夏季风环流和降水的年际关系.多模式集合(MME)预估结果表明,在全球变暖背景下,与20世纪末期(1970—1999年)相比,到21世纪末期(2070—2099年),春季北半球Hadley环流的年际变率强度将减弱,减弱幅度达32%.随着春季Hadley环流年际变率的减弱,其与夏季西太平洋副热带高压和东亚夏季风强度的联系将变弱.MME模拟结果还显示,春季Hadley环流与夏季东亚西风急流和降水的关系也降低,但各单个模式间存在较大差异.Observations indicate that spring Hadley circulation is tightly linked to East Asian summer circulations and precipitation on the interannual timescale. Whether does such a relationship as in the observation tend to change under the background of global warming in the future？ To answer this question, five climate models （GFDL_CM2_0, GFDL CM2_1, IAP_ FGOALS 1. 0g, NCAR_CCSM, UKMO_HADCM3）, which can well reproduce the observed interannual variability of spring Hadley circulation in the Northern Hemisphere and its linkage to East Asian summer atmospheric circulations and precipitation are firstly chosen based on overall assessment of models＇ simulation ability. Then, the potential change of the interannual variabilityof spring Hadley circulation and its interannual connection with East Asian summer circulations and precipitation under the A1B scenario are projected by using the outputs of these five climate models. To facilitate quantitative estimation of their change, five indices are exploited in this study. The Northern Hemispheric Hadley circulation index （HCI） is defined as the maximum value of the zonal mean mass stream function occurring within the latitudinal zone of 0°--30°N, and the western Pacific subtropical high index （WPSHI） as the 850 hPa geopotential height anomalies averaged over the region （10°N--30°N, ll0°E 150°E）. The difference of zonal wind anomalies at 850 hPa between the region （10°N--20°N, 100°E--150°E） and （25°N--35°N, 100°E--150°E） and that at 200 hPa between the region （25°N--35°N,80°°150°E） and （40°N--50°N,80°E 150°E） are used to define the East Asian summer monsoon index （EASMI） and the East Asian Jet index （EAJI）, respectively. The East Asian rainfall index is represented by mean precipitation over the region （27°N--32°N, 110°E--130°E）. The multi-model ensemble （MME） results show that the interannual variability of the Northern Hemispheric Hadley circulation in spring tends to decrease by23° in the late 2P�

关 键 词：HADLEY环流 东亚夏季风环流 年际变率 预估 

分 类 号：P467[天文地球—大气科学及气象学]