The tropical Atlantic Warm Pool is one of the main drivers of the marine intertropical convergence zone and the associated coastal Northeast Brazilian and West-African monsoons. Its meridional displacement is driven by the solar cycle, modulated by the atmosphere and ocean interactions, whose nature and respective proportions are still poorly understood. This paper presents a climatological study of the upper ocean and lower atmosphere contributions to the warm pool seasonal migration, using an Ocean General Circulation Model (OGCM). First, we provide quantitative, albeit simple, pieces of evidence on how the large amplitude of migration in the west, compared to the east, is mainly due to the strong east–west contrast of the background meridional SST gradient intensities, which is maintained by equatorial and eastern tropical upwellings. Our main results consist first in identifying a diagnostic equation for the migration speed of the two meridional boundary isotherms of the Warm Pool, expressed in terms of the various mixed-layer heat fluxes. We then evidence and quantify how, in general, the migration is forced by air–sea fluxes, and damped by ocean circulation. However, remarkable controls by the ocean are identified in some specific regions. In particular, in the northwestern part of the Warm Pool, characterized by a large temperature inversion area, the boreal spring northward movement speed depends on the restitution of the solar heating by the thermocline. Additionally, over the southern part of the Warm Pool, our study quantifies the key role of the equatorial upwelling, which, depending on the longitude, significantly accelerates or slows down the summer poleward migration.

中文翻译：

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OGCM中控制大西洋暖池季节性经向迁移机制的气候学研究

热带大西洋暖池是海洋热带辐合带和相关的巴西东北部沿海和西非季风的主要驱动力之一。它的经向位移是由太阳周期驱动的，由大气和海洋相互作用调节，其性质和各自的比例仍然知之甚少。本文使用海洋环流模型 (OGCM) 对上层海洋和低层大气对暖池季节性迁移的贡献进行了气候学研究。首先，我们提供了定量的、尽管很简单的证据，说明与东部相比，西部的大规模迁移主要是由于背景经向海温梯度强度的强烈东西向对比，由赤道和东部热带上升流。我们的主要结果首先包括确定暖池两个经向边界等温线迁移速度的诊断方程，用各种混合层热通量表示。然后，我们证明并量化了迁移通常如何受到海气通量的推动，并受到海洋环流的抑制。然而，在某些特定区域发现了海洋的显着控制。特别是在温池西北部，逆温区大，北春北移速度取决于温跃层对太阳加热的恢复。此外，在暖池的南部，我们的研究量化了赤道上升流的关键作用，这取决于经度，