太平洋和印度洋在南海夏季风爆发年代际变化中的作用

利用1951～1998年多种大气和海洋资料,研究了太平洋和印度洋在南海夏季风爆发中的作用.结果表明,影响南海夏季风爆发早晚的因素存在着年代际变化:1951～1970年,印度洋起主要作用;1970～1998年西太平洋起主要作用.该年代际变化主要是1970年前后北极涛动(AO)的跃变以及西太平洋副高强度变化的结果.1951...     

热带太平洋海气耦合过程对印度洋年际变化的影响

利用中等复杂程度的2.5层海洋模式和大气环流模式ECHAM4组成的海气耦合模式,模拟分析了热带太平洋和印度洋的气候变化以及年际变化特征。该模式较好地模拟了ENSO现象的空间分布及其不规则的周期变化特征,以及热带印度洋的主要变化特征。通过数值试验,初步研究了太平洋耦合过程对印度洋年际变化的影响。结果显示,当存在太平洋耦合过程时,模拟的印度洋偶极子(IOD)正(负)事件的发生频率比无太平洋耦合情形时有所减少(增加)。该变化是太平洋耦合变量通过海气耦合过程对印度洋海表面平均风场进行调整,进而引起热带印度洋温跃层深度东西梯度改变的结果。     

热带印度洋Rossby波的基本特征

<正>海洋斜压长Rossby波在海洋动力学中占据重要地位,是物理海洋学研究的一个重要任务。它维持并影响大洋西边界流,是海盆内能量传播的主要机制,是海洋对大气驱动的主要响应现象(Pedlosky,1979;Gill,1982)。20世纪70年代以来,XBT资料的积累使人们能够从水文资料中,特别是次表层海温的变化中发现大尺度Rossby波的存在依据(White,1977;Kessler,1990),且集中在     

热带印度洋Rossby波的基本特征

Long wavelength baroclinic oceanic Rossby waves are of interest because they are the main mechanism of energy transfer among the oceanic basins as the rotating fluid adjusts under the forcing of gravity and buoyancy,They play an important role in dynamics and thermodynamics in the ocean.The signature of them is evident from the altimeter measurements.Sea surface beight derived from the multiple ocean satellite altimeter missions over 1993～2008 is analyzed to systematically investigate the characteristics of the Rossby waves in the tropical Indian Ocean,by jointly adopting 2D-FFT,2D-Radon Transform,Complex Empirical Orthogonal Function and the classic linear theory methods.Results are as follows.The energy of Rossby wave is mainly concentrated between 5°S～18°S.Annual Rossby wave can be observed all over the whole badin,whereas semi-annual Rossby wave can bw only detected in the equatorial area, and inter-annual Rossby wave in the off-equatorial region.The phase speeds of Rossby waves detected from altimeter satellites are basically in agreement with the calculation based on the classic linear theory, but the former are some slower(faster) north(south)of 15°S than the later,Furthemore,it is indicated from the CEOF analysis that the annual Rossby waves is apparent in the Bay of Bengal,Arabian Sea ,and the open south Indian Ocean,whereas inter-annual Rossby wave mainly presents in the south Indian Ocean ,and eastward Kelvin wave is dominant along equator.     

太平洋内部副热带-热带经向翻转环流的季节变化特征

太平洋内部副热带-热带经向翻转环流(subtropical-tropical cell,STC)是连接热带和副热带的海洋通道.由于以往海洋观测资料的匮乏,前人多利用海洋模式数据进行研究,且仅限于沿单一纬度上的STC的分析,较少涉及沿不同纬度的STC的季节变异规律.利用地转海洋学实时观测阵(array for real-...