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.

本研究首次估计了通过地球模拟器进行的全球涡流海洋循环模型（OGCM），估计了海洋中尺度变异性引起的子午热传输，例如世界海洋中的中尺度涡流。极端涡流热传输通常主要是西部边界电流和南极圆极电流，以及赤道区域的赤道涡流热传输，与先前对较粗糙的OGCMS的研究的结果相似。在纬度海洋中，如此重要的极向涡流传输表明，涡流作用于弱弱的子午背景温度梯度，如线性斜压斜率理论所预期的那样。然而，有趣的是，特别是对于黑发延伸和墨西哥湾流，赤道涡流传输发生在这些电流的南部坦率的地下层中。赤道涡流热传输的主要机制在这些电流之间有所不同。对于黑发延长，在电流路径的赤道弯曲时，最初通过赤道电流升级了最初分布在电流路径上的温水。对于海湾流，海湾流形成圆形的温暖涡流沿南部再循环回旋的东部边缘迁移赤道。