【作者】 武扬；

【导师】 程国胜； 舒业强；

【作者基本信息】 南京信息工程大学 ， 应用数学， 2012， 硕士

【摘要】 地球气候系统最重要的组成部分是海洋,其吸收的太阳辐射绝大部分储存于表层海洋(混合层)中。这些能量输送给大气,驱动大气运动并影响气候的变化。海洋上层热结构的变动对气候和大气环流有着十分重要的影响。海洋热含量比海表面温度(SST)更稳定,对气候持续发展的作用更大。中国近海海温对我国的汛期降水和气候变化有一定的影响,其中南海海洋热含量的变化对东亚季风和我国气候异常有着重要影响。因此,研究南海海洋热含量的变化有助于认识南海的动力过程和其海气相互作用机理,还有利于亚洲季风变化规律和中国气候预测等方面的研究。本文首先评估了所使用的资料表明CORA资料能更好地反映参量的一些细微特征。分析了SST的季节及年际变化特征,第二模态显示的是SST对由风引起的潜热释放的响应特征。第三模态刻画了冬夏转换季的分布特征,主要揭示了东北-西南走向的锋面特征。SST年际变化与ENSO密切相关。利用]RMM/TM卫星遥感SST数据,对南海SST的季节内变化规律进行了分析,南海SST的季节内振荡与纬向风分量、经向风应力、潜热通量有密切关系。随后利用1871-2008年SODA资料分析了南海混合层深度(MLD)的季节及年际变化特征。表明：季风通过流场调整对南海MLD的时空分布特征有显著的影响；南海MLD的距平变化总体呈上升趋势,南海南部MLD的距平变化趋势与北部有显著差异；SO1指数对滞后的南海各个区域有较好的相关性；MLD年际变化的空间分布第一模态整体呈单极型,最大变率分布在南海南部,由南往北逐渐减小；第二模态呈偶极子型。回归分析表明南海南部深水区域呈现增深的趋势,而吕宋海峡至南海北部陆架区呈变浅趋势。最后分析了南海上层海洋热含量的季节、年际变化情况,及其与海气界面热通量的关系,南海热含量、净热通量具有明显的季节变化特征,且二者有很好的相关性。南海热含量的年际变化特征最显著的周期为29个月,EOF第一模态的空间分布越南外海有一正值的最大变率中心,吕宋海峡为一负值的最大变率中心。第二模态的空间分布为整个深水海盆为正值其余海域为负值。在典型的ENSO暖、冷年与热含量有很好的响应。南海热含量的年代际变化特征表现为整体上升的趋势,突变年份发生在1912年左右。利用观测资料计算了南海120°E断面总的体积、热、盐输运量,基于CORA资料计算的南海域际热、盐、体积输运给出了南海各海峡的输运情况,南海年平均体积、热、盐输送分别为：0.377Sv、0.1567Pw,-1.0635Gg/S。更多还原

【Abstract】 Oceans are the important part of the climate system, the most of the solar radiation absorded by oceans is stored in the surface oceans (mixed layer). The atmosphere is drived and climate is influenced by the energy. The variability of the thermal structure in the mixed layer plays a important role in the climate and atmospheric circulation. The ocean heat content is stabler than sea surface temperature (SST), and has more important affect. The SST of the coastal China seas can effect its area even the precipitation in the flood season in the interior. The variability of the heat content in the South China Sea can influence the East Asian monsoon and the anomalies of the climate. So the exploration of the heat content can make us understand the dynamic processes and the mechanism of the air-sea interaction easily, and the variability of the Asian monsoon and the prediction of Chinese climate can be understanded well.The assessment of CORA has benn done, indicating that CORA can represent more subtle features than SODA. Te seasonal and interannual variability of SST in the coastal China seas can be well portrayed by CORA data. The second mode of EOF reveals the SST response to wind-induced latent heat. The third mode presents the northeast-southwestern distribution of SST front, which is coincident to the transitionally seasonal characters between summer and winter, the interannual variability of SST is closely related to ENSO.Based on the TRMM/TMI satellite remote sensing data during1998to2010, the intra-seasonal variabilities of the SST in the South China Sea are analyzed, and the possible mechanism for generating the intra-seasonal SST variabilities is also discussed. Intraseasonal oscillation has closed relationship with zonal wind component, meridional wind stress and the latent heat flux. Based on SODA data, the characteristics of the seasonal and inter-annual variations of the mixed layer depth (MLD) in the South China Sea (SCS) are derived. Data analysis indicates that the monsoon has an obvious impact on the temporal and spatial features of the mixed layer in the SCS through the adjustment of the current field. The MLD of the SCS has a deepening trend in general; however the differences between northern and southern areas are obvious. The first mode shows that the variability is the same in the whole area of SCS basically.And the second mode shows that the variability is dipole-type. The trend of MLD in the SCS is different form north and south, from the Luzon Strait along the continental slope south of China is shallowing, and the other in the deep basin of the southern SCS is deppening.Analysis shows that heat content in SCS has obvious seasonal variation close to SST, Net surface heat flux also shows the same variation. Results of spectrum show that there is about29months period. The first EOF mode note that there is a local maximum positive value centered at the east off Vietnam, and a local maximum negative value located at the northwest off Luzon Strait and the most sensitive area to water exchange between the SCS and the western Pacific. The spatial pattern associated with the second EOF mode (EOF2) is positive over the center of SCS, other area is negative. It is found that the variability has a good correspondence with ENSO events. Interdecadal variations of the heat content in the SCS expressed as upward trend. Observational ocean temperature and salinity data are used to calculate volume transport, heat transport and Salinity transport across120°E sections. Base on the CORA data, the monthly and annual mean volume heat and salt transports through the open boundaries of the SCS are reported. The computation shows that the net volume, heat and salt transports of SCS is0.377Sv、0.1567Pw、-1.0635Gg/s respectively.更多还原