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夏季长江中下游和华南两类雨型的环流特征及预测信号 被引量:12
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作者 赵俊虎 杨柳 +1 位作者 曾宇星 封国林 《大气科学》 CSCD 北大核心 2016年第6期1182-1198,共17页
利用中国南方66站降水观测资料和NCEP/NCAR再分析资料,采用经验正交函数分解(EOF)、合成分析和相关分析等方法,对夏季长江中下游和华南两类雨型进行了划分,对比分析了两类雨型同期大气环流和前期海温及环流的差异,以探讨两类雨型的形成... 利用中国南方66站降水观测资料和NCEP/NCAR再分析资料,采用经验正交函数分解(EOF)、合成分析和相关分析等方法,对夏季长江中下游和华南两类雨型进行了划分,对比分析了两类雨型同期大气环流和前期海温及环流的差异,以探讨两类雨型的形成机制及前期预测信号。结果表明:20世纪80年代之前华南型出现的频次较高,之后长江中下游型出现频次增多;长江中下游型年西太平洋副热带高压(副高)偏强偏西偏南,东亚夏季风(EASM)偏弱,副热带西风急流位置偏南,乌拉尔山阻塞高压(乌阻)和鄂霍次克海阻塞高压(鄂阻)较强,欧亚中高纬以经向环流为主,冷暖空气在长江中下游辐合,导致长江中下游降水偏多;华南型年大气环流与长江中下游型年大体相反,登陆华南的台风偏多,冷暖空气在华南地区辐合,导致华南地区降水偏多;其中副高的脊线位置和中高纬阻塞强弱是长江中下游型和华南型形成的关键因素。两类雨型前期海温分析表明,长江中下游型年,前冬赤道中东太平洋和印度洋偏暖,为典型的东部型El Ni?o,副热带南印度洋偶极子(SIOD)呈负位相,春季El Ni?o衰减,SIOD负位相也减弱,但印度洋持续增暖;华南型年,前冬和春季的海洋演变与长江中下游型年大体相反;关键区域海温与长江中下游夏季降水(YRR)和华南夏季降水(SCR)的年际关系存在年代际变化,YRR和SCR与前冬Ni?o3.4指数、SIOD指数和春季热带印度洋全区一致海温模态(IOBW)指数的相关关系在80年代之后逐步减弱,这主要是由于这三个关键海温指数与EASM及副高脊线的相关关系在80年代之后逐步减弱;两类雨型前期大气环流差异分析表明,春季大气环流的差异性要比前冬显著,长江中下游型年,春季副高、南海副高、马斯克林高压(马高)、澳大利亚高压(澳高)均偏强,大西洋欧洲区极涡强度偏弱,北太平洋涛动(NPO)呈正位相;华南型年春季的关键环流系统异常不明显,仅大西洋欧洲区极涡强度偏强,NPO呈负位相。前期海温演变及春季大气环流关键系统的异常可以作为两类雨型年的一些预测信号。 展开更多
关键词 夏季雨 长江中下游型 华南 海温 大气环流
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A Typical Mode of Seasonal Circulation Transition: A Climatic View of the Abrupt Transition from Drought to Flood over the Middle and Lower Reaches of the Yangtze River Valley in the Late Spring and Early Summer of 2011 被引量:3
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作者 ZONG Hai-Feng BUEH Cholaw +2 位作者 CHEN Lie-Ting JI Li-Ren WEI Jie 《Atmospheric and Oceanic Science Letters》 2012年第5期349-354,共6页
In this study, the seasonal transition of precipitation over the middle and lower reaches of the Yang-tze River Valley (YRV) from late spring to early summer is investigated. The results show that the seasonal transit... In this study, the seasonal transition of precipitation over the middle and lower reaches of the Yang-tze River Valley (YRV) from late spring to early summer is investigated. The results show that the seasonal transition of precipitation exhibits multi-modes. One of these modes is characterized by an abrupt transition from drought to flood (ATDF) over the middle and lower reaches of the YRV in the seasonal transition of precipitation. It is shown that the ATDF event from May to June 2011 is simply one prominent case of the ATDF mode. The ATDF mode exhibits an obvious decadal variability. The mode has occurred more frequently since 1979, and its amplitude has apparently strengthened since 1994. From the climatic view, the ATDF mode configures a typical seasonal circulation transition from winter to summer, for which the winter circulations are prolonged, and the summer circulations with the rainy season are built up early over the YRV. 展开更多
关键词 abrupt transition from drought to flood ex-tended empirical orthogonal function seasonal transition
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Improving Conservation of Cranes by Modeling Potential Wintering Distributions in China 被引量:3
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作者 焦盛武 曾晴 +1 位作者 孙工棋 雷光春 《Journal of Resources and Ecology》 CSCD 2016年第1期44-50,共7页
Habitat management is essential for the conservation of wildlife, especially cranes. Here, we collected occurrence data at wintering grounds for four cranes (Leucogeranus leucogeranus, Grus monacha, Antigone vipio an... Habitat management is essential for the conservation of wildlife, especially cranes. Here, we collected occurrence data at wintering grounds for four cranes (Leucogeranus leucogeranus, Grus monacha, Antigone vipio and G. grus) and analyzed associated environmental variables to model and project overall potential wintering habitat using Maxent. ENMTools was used to calculate the degree of niche overlap among cranes. Results showed that lakes in the middle and lower reaches of the Yangtze River are main habitats for the four focal species. Inland water and coastal wetlands in Jiangsu are also potential wintering areas. G. grus spreads over central and eastern China. The four cranes show tight niche overlap in the middle and lower reaches of the Yangtze River. Poyang Lake is one of the most important habitat sites for all four cranes, according to modeling and niche overlap results. Poyang Lake is cut into a dozen nature reserves, but a bigger nature reserve or system would be more effective for cranes. The conservation of these four crane species will be improved on the basis of this study. 展开更多
关键词 CRANES middle and lower reaches of Yangtze River HABITAT MAXENT ENMTools
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