热带太平洋-印度洋海温异常综合模的数值模拟

通过数值模拟及结果的合成分析,对热带太平洋-印度洋异常海温综合模态的三维热力结构、动力结构及其发生发展的可能机制进行了研究.数值模拟结果的分析表明,太平洋、印度洋海温异常的综合模态在表层、次表层的表现都很明显,即在赤道西印度洋、中东太平洋的海温偏高(低)时,赤道西太平洋、东印度洋的海温偏低(高),该模态还存在着显著的年变化特征、年际变化特征以及年代际变化特征.数值模拟的合成分析结果表明,异常的海表风应力引起表层洋流异常,表层洋流异常及由其引起的海表高度异常可导致次表层海水环流的异常,海洋环流异常导致的平流热输送异常是海温形成异常综合模态的主要原因之一,垂直输送是形成次表层海温综合模态的主要原因.平流热输送过程对海表温度变异的贡献是:在事件发生到盛期阶段促进了次表层海温异常综合模态的形成,在盛期到消亡阶段次表层的平流过程阻碍其进一步发展;短波辐射是海洋的主要热力来源,海表面异常的净短波辐射通量、潜热通量是表层海温形成异常模态的主要热力学原因,异常的海表面净短波辐射通量、潜热通量、感热通量在到达盛期阶段后抑制其进一步发展.

Numerical Simulation of the Tropical Pacific-Indian Ocean Associated Temperature Anomaly Mode

Three-dimensional thermal and dynamic structures of the Pacific-Indian Ocean associated temperature anomaly mode and the forming and evolvement mechanism of the associated mode are studied in terms of numerical modeling and composite analyses. The sea temperature anomalies in the equatorial western Indian Ocean and the e-quatorial eastern Pacific are reversed with that in the equatorial eastern Indian Ocean-western Pacific. This associ-ated mode has annual, interannual, and interdecadal variability.The composite analyses of modeling results disclose that the circulation anomaly caused by the anomalous surface wind stress is one of the main dynamical reasons and the vertical transport is important to the subsurface associated sea temperature mode. In addition, anomalous net short wave radiation flux and latent heat flux are the main thermodynamic reasons to the associated mode forming.From the occurrence associated to its crest, the anomalous surface advection and subsurface vertical transportation spur its evolution, while anomalous net short wave radiation flux, latent heat flux, sensible heat flux, and subsur-face advection restrain its further evolution