【作者】 李江萍；

【导师】 孙即霖； 王东晓；

【作者基本信息】 中国海洋大学 ， 气象学， 2004， 硕士

【摘要】 本文通过对SODA全球海洋同化分析月平均资料和COADS全球表层月平均气候资料的分析，研究了南太平洋热带(TC)和副热带(STC)水平环流区内的热含量变化，分析讨论了与热含量变化相关的环流指数、温度平流和Sverdrup输运对热带环流和副热带环流间热量交换的影响。通过对不同深度海温和不同纬度上海温在不同时间尺度的全球空间分布的对比分析，讨论了大尺度海气相互作用对年代际气候变化的影响。 研究发现，热带海区的热含量存在大约4年左右年际尺度的变化，而在副热带海区主要存在12年左右年代际尺度的振荡。上述两个海区热含量的变化主要受温度平流的影响，同时还受到海-气界面热交换的影响，主要过程包括长、短波辐射，潜热和感热通量。对热含量变化的贡献，海-气界面热交换的影响在副热带区域比在热带区域大；温度平流在热带区域的贡献比在副热带区域显著。两个区域之间存在着相互作用，与风驱经向环流有关。 采用将相反位相相减的方法比较了年际和年代际两种时间尺度气候变化的时空分布特征。研究发现：在空间分布上两者在赤道海区的变化都与海洋温度跃层具有密切的联系，两者对赤道海洋影响的水平分布类似。大气对两者暖位相的响应都对应着异常暖赤道海区上空西风异常的增强。两者的差异主要表现在：对应ENSO时间尺度的异常与季节变化具有密切的关系，而对应年代际时间尺度变化的异常似与季节变化无关。在空间分布上，年代际变化在中高纬度对应与赤道东太平洋相反位相的变化。导致赤道东太平洋增暖的原因也有很大的差异：年际时间尺度SST异常的变化与海区上空的纬向风异常关系密切，而年代际时间尺度SST异常的变化与海区上空的经向风异常关系密切。 用大尺度海洋大气相互作用的观点分析了影响年代际变化的可能机制。研究发现：南印度洋西风带平直西风的出现和异常增强有利于副热带印度洋表层海水年代际时间尺度的增暖，有利于相同纬度南太平洋表层海水年代际时间尺度的温度降低。南美洲西海岸外太平洋南风的减弱有利于赤道东太平洋年代际时间尺度的增暖。更多还原

【Abstract】 Based on the SODA and COADS, the variability of heat content for tropical and subtropical cells in the Southern Pacific have been studied. Circulation indices, thermal advection and wind stress curl that relate to heat content have also been studied. At the same time, In order to find the probable reasons that lead to decadal variability author analyze spacial distribution of sea temperature at different depth and different latitude in different time scale.The variabilities of heat content in the tropical, subtropical cells respectively dominated by interannual and decadal . As an open system, the variability of heat content not only affected by thermal advection, but also affected by interaction of air-sea. The sum of long-radiate, short-radiate, latent heat and sensible heat has more important affection than thermal advection in the subtropical cell; while in the tropical cell, the contribution of thermal advection is greater than interaction of air-sea. The two cells may be connected with mechanism of meridional overturning circulation.Using method of magnifying signal of climatic variability, and comparing spacial distribution of interannual variability with that of decadal variability, author have found that : variability of ENSO and decadal variability are connected with thermocline in the spacial distribution; they have similar horizontal distribution for equatorial sea. Warm phases of interanuual and decadal variability correspond to intensity of anomalous western wind above equatorial sea .The differences are just as following: anomaly of ENSO is connected with seasonal change, while decadal variability may don’t relate to seasonal change. The spacial distribution of decadal variability between eastern equatorial Pacific and higher latitudes are out of phase. The reasons leading to warming of eastern equatorial pacific are greatly different: the SSTA of interannual variability is related to anomaly of zonal wind, while SSTA of decadal variability is connected with anomaly of meridonal wind.The probable reasons that may lead to decadal variability are analyzed throughthe view of interaction of aie-sea in large-scale time. The results show that : westerly belt and it’s intensity in southern Indian ocean may result in warming of SST in subtropical cell of southern Indian ocean in decadal time scale, while it can result in cooling of SST of southern Pacific in the same latitude . Weakening of southern wind coming from Pacific in western shore of south American is good to warming of SST in eastern equatorial Pacific.更多还原