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

本文首次利用地球模拟器（Earth Simulator）进行的全球涡旋解析海洋环流模式（OGCM）估算了世界海洋中尺度涡旋等海洋中尺度变率引起的经向热输运。西界流和南极环极流总体上以向极地的涡旋热输送为主，赤道地区以向赤道的涡旋热输送为主，这与以往使用粗分辨率ogcm的研究结果相似。中纬度海洋中如此显著的极地涡旋热输送表明，涡旋减弱了强经向背景温度梯度，这与线性斜压不稳定理论的预期一致。然而，有趣的是，特别是对于黑潮伸展和墨西哥湾流，赤道涡旋热输送发生在沿这些流的南部frank的次表层。这些海流对赤道涡旋热输运的主导机制是不同的。对于黑潮伸展，当海流走向赤道时，原本分布在海流路径上的温水被海流向赤道平流。对于墨西哥湾流，在墨西哥湾流上形成的圆形暖涡流沿南部再环流环流的东部边缘向赤道方向迁移。

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.