近千年来三个气候特征时期东亚夏季风的模拟对比  

Comparison of East Asian Summer Monsoon in Three Climate Typical Periods during Last Millennium Based on ECHO-G Simulation

作　　者：况雪源[1] 刘健[2] 林惠娟 王红丽[2] 提汝媛[2] 

机构地区：[1]南京大学大气科学学院,江苏南京210093 [2]湖泊与环境国家重点实验室,中国科学院南京地理与湖泊研究所,江苏南京210008 [3]浙江省气象科学研究所,浙江杭州310017

出　　处：《地球科学进展》2010年第10期1082-1090,共9页Advances in Earth Science

基　　金：中国科学院知识创新工程重要方向项目“过去2000年东亚季风气候演变及其与人类相互作用研究”(编号:KZCX2-YW-315);国家自然科学基金项目“中国千年气候变化数值模拟与机理研究”(编号:40890054)和“中国东部近千年来土地利用变化对东亚季风气候影响的模拟研究”(编号:40871007)资助

摘　　要：利用全球海气耦合气候模式ECHO-G的近千年连续积分资料,选取与降水关系较好的东亚夏季风指数,对不同气候特征时期的东亚环流及季风影响因子进行了探讨。结果表明用海陆热力差异定义的东亚夏季风指数Isun在年际尺度上较好地体现了长江流域及华北地区降水的变化,而利用850 hPa纬向风场定义的指数Iwang在年代际尺度上较好地体现了长江流域的降水变化。从不同气候特征时期的环流来看,中世纪暖期夏季风最强,东亚大陆降水明显偏多,现代暖期夏季风较之有所减弱,而小冰期则是夏季风最弱的时期,东亚大陆的降水明显偏少。不同气候特征时期夏季风指数与海温的相关表明,ENSO事件对东亚夏季风的影响在现代暖期有所增强,而与外部强迫因子的相关揭示出中世纪暖期有效太阳辐射变化是影响东亚夏季风变化的主要因子,现代暖期则是温室气体对夏季风的影响更重要。The East Asian Summer Monsoon（EASM） has long been focused owing to its crucial role in modulating the East Asian climate.Although many results have been obtained from modern monsoon research,it is still difficult to further study the mechanism of paleo-monsoon due to lack of meteorological data.In this paper,monsoon index is chosen to depict the intensity change of EASM in order to understand the monsoon differences of three climate typical periods based on the modeling results derived from ECHO-G coupled climate model for the last millennium.The results indicate that the index Isun which is defined with thermal contrast between land and sea is well associated with the precipitation of the Yangtze River Basin and North China on interannual time scale,while the index Iwang defined with zonal wind at 850 hPa is in accordance with the precipitation of the Yangtze River Basin on decadal time scale.The general circulation differences of three climate typical periods reveal that EASM is the strongest in the Medieval Warm Period（MWP）,then the Present Warm Period（PWP） and that of the Little Ice Age（LIA） is the weakest,which is corresponding to the precipitation magnitude in East Asian continent in each period.The correlations between the summer index and SST in three climate typical periods show that the impact of ENSO on EASM has been reinforced in PWP.Further analysis reveals that effective solar radiation is the main controlling factor on EASM in MWP but the greenhouse gases plays primary role in EASM in PWP.

关 键 词：近千年 气候特征时期 东亚夏季风 模拟 

分 类 号：P434[天文地球—大气科学及气象学]