摘要: |
本文基于一层半海洋模式和SVD(Singular Value Decomposition)大气模式构建了一个简单的海气耦合模式, 引入热通量的作用, 分析ENSO影响热带印度洋地区的动力学和热力学耦合过程。其中, 使用统计大气模式, 由给定的SST(Sea Surface Temperature)异常得到风应力异常, 进而驱动海洋环流反馈给SST, 完成海气的动力耦合; 使用块体经验公式由SST异常和风场异常计算热通量异常, 直接作用于SST, 实现海气的热力学耦合。动力耦合实验揭示, 太平洋第一EOF(Empirical Orthogonal Functions) 模态与观测基本吻合。并且模拟Ni?o 3指数存在两年左右的谱峰周期。这说明, 海气动力学耦合是ENSO生成的主要因素。热力耦合的加入是为了考察ENSO影响热带印度洋的热力学效应。同时考虑动力和热力耦合的实验结果表明, 热带太平洋暖异常中心更加接近观测值, 热带印度洋出现海盆尺度海温正异常。这意味着热带太平洋的ENSO信号通过海气界面的热量交换实现对热带印度洋地区的遥强迫, 导致印度洋海盆尺度增暖。 |
关键词: ENSO IOD(Indian Ocean Dipole) 热力学耦合 |
DOI:10.11693/hyhz201306008 |
分类号: |
基金项目:国家自然科学基金项目, 41176017 号; 山东省基金委项目, JQ201010 号; 国家重大科学研究计划项目, 2010CB950402。 |
附件 |
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AN INTERMEDIA AIR-SEA COUPLED MODEL FOR THE INDO-PACIFIC OCEAN |
LIU Yan-Song1,2, WANG Fa-Ming1
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1.Institute of Oceanology, Chinese Academy of Sciences;2.Graduate University, Chinese Academy of Sciences
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Abstract: |
An intermedia couple model with heat-flux effect was used in this study to analyze thermodynamical air-sea feedbacks in the tropical Indian Ocean forced by El Ni?o-Southern Oscillation (ENSO). To achieve the dynamical air-sea feedback, an empirical model was constructed in statistical technique to determine wind stress anomalies from model sea surface temperature (SST). To achieve thermodynamical air-sea feedback, a bulk formula was used to calculate heat flux from model SST and wind speed anomalies. Results show that the first empirical orthogonal function mode accorded with observation in the tropical Pacific, and has about 2-year interannual variability from power spectrum of Ni?o 3 index, suggesting that the dynamic air-sea feedback controlled the ENSO. In addition, results indicate that the center of positive anomaly in the tropical Pacific showed strong ENSO signals, more-positive anomaly was generated in the tropical Indian Ocean, especially in the West Indian Ocean, which are similar to the observation data. Therefore, ENSO acts as an atmospheric tele-connector linking the tropical Indian Ocean with tropical Pacific via air-sea heat-flux changes for generating positive anomaly in these basins. |
Key words: ENSO IOD(Indian Ocean Dipole) thermodynamic feedback |