An estimation of oceanic eddy heat transport in a high resolution Ocean General Circulation Model

高分辨率海洋环流模型中海洋涡热传输的估计

• 批准号: 21740336
• 负责人: AOKI Kunihiro
• 金额: $ 2.83万
• 依托单位: Hokkaido University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Young Scientists (B)
• 财政年份: 2009
• 资助国家: 日本
• 起止时间: 2009 至 2011
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-21740336/
• 关键词: 海洋中規模渦; 熱輸送; 高解像度海洋数値シミュレーション; 中規模渦; 海洋モデル; 全球; 海洋物理学

The present study, for the first time, estimates meridional heat transport induced by oceanic mesoscale variability such as mesoscale eddy in the World Ocean using a global eddy-resolving Ocean General Circulation Model(OGCM) conducted by the Earth Simulator. Poleward eddy heat transports are generally predominant for the Western Boundary Currents and the Antarctic Circumpolar Current, and along with equatorward eddy heat transport in the equatorial region, as similar to the results from previous studies with coarser resolution OGCMs. Such a significant poleward eddy heat transport in mid-latitude oceans suggests that the eddies act to weaken strong meridional background temperature gradients as expected from the linear baroclinic instability theory. However, interestingly, especially for the Kuroshio Extention and the Gulf Stream, equatorward eddy heat transport occurs in subsurface layer along the southern frank of these currents. The dominant mechanism of the equatorward eddy heat transport is different between these currents. For the Kuroshio Extension, warm water originally distributed on the current path is advected equatorward by equatorward current in the event of equatorward meandaring of the current path. For the Gulf Stream, warm eddies with circular shape formed on the Gulf Stream migrates equatorward along eastern rim of the southern recirculation gyre.

本研究，第一次，估计纬向热输送引起的海洋中尺度变化，如中尺度涡在世界海洋使用全球涡分辨海洋环流模式（OGCM）进行的地球模拟器。西边界流和南极绕极流的向极涡热输送一般占主导地位，并沿着赤道地区的向赤道涡热输送，与以前用较粗分辨率OGCM研究的结果相似。这种显着的极向涡热输送在中纬度海洋表明，涡的作用，以削弱强纬向背景温度梯度的预期从线性斜压不稳定理论。然而，有趣的是，特别是黑潮延伸区和墨西哥湾流，赤道向涡动热量输送发生在次表层沿着这些电流的南部弗兰克。这两种海流的向赤道涡动热输送的主导机制是不同的。黑潮延伸区在向赤道弯曲的情况下，原本分布在流路上的暖水被向赤道流向赤道平流输送，墨西哥湾流上形成的圆形暖涡沿南部再循环环流沿着东缘向赤道迁移。