北大西洋海温异常对广义东亚夏季风和印度夏季风交界面年际变化的影响机制

发布时间：2017-12-28 01:02

本文关键词：北大西洋海温异常对广义东亚夏季风和印度夏季风交界面年际变化的影响机制　出处：《云南大学》2016年博士论文　论文类型：学位论文

【摘要】：东亚夏季风与印度夏季风交界面是表征亚洲夏季风两个子系统(东亚夏季风与印度夏季风)相互作用的重要指标之一。其年际变化对理解和预测亚洲夏季风环流及其降水具有重要意义。本文首先在前人研究工作的基础上,对东亚夏季风与印度夏季风交界面进行了改进,提出了基于广义位温定义下的东亚夏季风与印度夏季风交界面GIIE,并获得了相应的GIIE指数。并利用NOAA二十世纪再分析资料V2、hadley中心月平均海温资料,综合应用相关分析、合成分析、经验正交函数分解(EOF)、奇异值分解(SVD)、T-N flux诊断等方法和数值模拟方法,系统地研究了前期到同期北大西洋海温异常对广义东亚夏季风与印度夏季风的交界面GIIE年际变化的影响机制。揭示了北大西洋三极型海温异常通过激发北大西洋-丝路型遥相关影响GIIE年际变化的物理过程。并用ECHAM5-NEM02.3数值模式对分析结果进行了分析和验证。主要结论如下：(1)广义位温的概括公式及广义定义下的交界面。在前人广义位温定义的基础上,用EOF提取各种大气不均匀饱和状况的权重,按照权重线性组合得到能综合概括不同非均匀饱和状态的广义位温的线性组合公式。用这个广义位温的线性组合公式重新计算了东亚夏季风与印度夏季风的交界面及其指数,并将其称为基于广义位温的东亚夏季风与印度夏季风交界面(GIIE)。由于广义位温的线性组合能更真实地描述大气的“不完全饱和”状态,因此GIIE能更好地描述东亚夏季风与印度夏季风交界面的演变。(2)北大西洋影响GIIE年际变化主导模态的提取。通过对多年春季到夏季北大西洋海温异常和GI IE多年位置分布做奇异值分解SVD后发现,从前期春季到同期夏季北大西洋三极型海温分布与GIIE年际变化存在显著的关系。进一步对北大西洋海温异常做GIIE指数的合成分析确认,北大西洋三极型海温异常是两个场耦合关系的主导模态。(3)北大西洋三极型海温影响GIIE年际变化的物理过程。通过对基于SVD1左场(海温场)时间序列和右场(GIIE)时间序列做高层经向风异常、位势高度异常和波通量的合成分析,得到了北大西洋三极型海温异常对GIIE的影响机制-北大西洋-丝路型遥相关,揭示了前期到同期北大西洋三极型海温影响GIIE位置的物理过程：前期北大西洋三极型“+、-、+”(“-、+、-”)海温异常持续到夏季,并激发北大西洋-丝路型遥相关,夏季北大西洋-丝路型沿大圆路径传播,相应的位势高度异常沿大圆路径呈“负-正-负-正-负-正”(“正-负-正-负-正-负”)分布特征,环流场则沿大圆路径呈“气旋-反气旋-气旋-反气旋-气旋-反气旋”(反气旋-气旋-反气旋-气旋-反气旋-气旋)分布特征,导致西太平洋副高异常偏强偏南(偏弱偏北),进一步导致GIIE位置异常偏东(偏西)。(4)北大西洋海温异常影响GIIE年际变化的数值模拟。所用的ECHAM5-NEM02.3模式能够比较好地模拟出北大西洋三极型海温的基本特征。分析耦合模式中异常风场、位势高度场和T-N通量对北大西洋三极型海温的响应,结果表明数值模式比较好地再现了观测事实分析中的北大西洋-丝路型遥相关及其导致的GI IE年际摆动,验证了北大西洋三极型通过北大西洋-丝路型影响西太平洋副高强度和位置进而影响GIIE的物理模型,所获结果也与第四章的分析结论一致。
[Abstract]:The East Asian summer monsoon and the India summer monsoon interface are one of the important indicators of the interaction between the two sub-systems of the Asian summer monsoon (the East Asian summer monsoon and the India summer monsoon). Its interannual variation is of great significance to understanding and predicting the Asian summer monsoon circulation and its precipitation. In this paper, based on previous studies, we improved the East Asian summer monsoon and India summer monsoon interface, and proposed the GIIE of the East Asian summer monsoon and India summer monsoon based on the generalized potential temperature, and obtained the corresponding GIIE index. And the use of NOAA in twentieth Century, Hadley V2 reanalysis data center SST data, correlation analysis, comprehensive application of synthetic analysis, empirical orthogonal function (EOF), singular value decomposition (SVD), T-N flux simulation method and numerical method of diagnosis, systematically study the influence mechanism of the North Atlantic SST anomalies over the same period the interface of GIIE generalized the interannual variations of East Asian summer monsoon and the summer monsoon in India. The physical process of the interannual variation of the North Atlantic tri - type sea temperature anomalies by stimulating the North Atlantic - silk teleconnection of the North Atlantic is revealed in the North Atlantic Ocean. The results of the analysis are analyzed and verified by the ECHAM5-NEM02.3 numerical model. The main conclusions are as follows: (1) the generalized formula of the generalized bit temperature and the interface under the generalized definition. Based on the definition of generalized potential temperature of predecessors, we extract the weight of all kinds of atmospheric non-uniform saturated conditions by EOF, and get a linear combination formula based on weight linear combination to generalize the generalized potential temperature of different non-uniform saturated states. Using the linear combination formula of the generalized potential temperature, we calculate the interface and index of the East Asian summer monsoon and the India summer monsoon, and call it the East Asian summer monsoon and India summer monsoon interface (GIIE) based on generalized potential temperature. Because the linear combination of generalized potential temperature can more accurately describe the "incomplete saturation" state of the atmosphere, GIIE can better describe the evolution of the East Asian summer monsoon and the India summer monsoon interface. (2) the extraction of the leading mode of the interannual variation of GIIE in the North Atlantic. Through the singular value decomposition SVD for many years from the spring to summer in the North Atlantic SST and GI IE, we find that there is a significant relationship between the three pole SST distribution in the North Atlantic and the GIIE interannual variation from the early spring to the same period. Further analysis of the North Atlantic sea temperature anomaly GIIE index has confirmed that the North Atlantic tri - polar sea temperature anomaly is the dominant mode of two field coupling relationships. (3) the physical process of the interannual variation of GIIE in the North Atlantic tri - polar sea temperature. Based on the SVD1 field (SST) based on the left and right field time series (GIIE) time series wind anomalies, geopotential height anomaly and the wave flux obtained by synthetic analysis of high-rise, the North Atlantic SST anomaly triode type impact mechanism of GIIE - the Silk Road North Atlantic teleconnection, reveals the influence of the physical process the location of GIIE over the same period prior to the North Atlantic SST: the North Atlantic triode triode type "+, -, +" ("+, -, -) SST anomalies continued to summer, and stimulate the North Atlantic teleconnection Silk Road, the spread of the Summer North Atlantic - Silk Road along the great circle path, the corresponding potential the height anomaly along the great circle path is" negative positive negative positive negative positive (positive negative positive negative positive negative ") distribution, circulation field along the great circle path is" - cyclonic anticyclonic cyclonic and anticyclonic cyclonic and anti cyclonic (anticyclonic - "cyclone anticyclone - - cyclone The distribution characteristics of anticyclone cyclones lead to the abnormal bias of the West Pacific subtropical high (the weaker North), which further leads to the anomalous eastward (West) position of the GIIE position. (4) the numerical simulation of the interannual variation of GIIE in the North Atlantic Ocean temperature anomaly. The ECHAM5-NEM02.3 model can be used to simulate the basic characteristics of the tri - polar SST in north the Atlantic. Response analysis of coupled model of abnormal wind, geopotential height and T-N flux of the North Atlantic SST triode type, the results show that the numerical model is well reproduced by the observation and analysis of facts in the North Atlantic - Silk Road and GI IE teleconnection to verify the interannual oscillation, the North Atlantic triode type effect of physical model GIIE then through the North Atlantic - silk road type influence the West Pacific subtropical high intensity and position, the results obtained with the fourth chapter analysis conclusion.
【学位授予单位】：云南大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：P425.42;P461.2

【相似文献】