The sea surface temperature (SST) beneath a tropical cyclone (TC) is of great importance to its dynamics; therefore, understanding and accurately estimating the magnitude of SST cooling is of vital importance. Existing studies have explored important influences on SST of TC translation speed, maximum surface winds, ocean thermal condition, and ocean stratification. But the influence of the TC wind radii (or collectively called the TC size) on SST has been largely overlooked. In this study, we assess the influence of wind radii uncertainty on SST cooling by a total of 15,983 numerical simulations for the western North Pacific during the 2014–2018 seasons. Results show a 6%–20% SST cooling error induced using wind radii from the Joint Typhoon Warning Center official forecast and a 35%–40% SST cooling error using wind radii from the operational runs of the Hurricane Weather Research and Forecasting (HWRF) model. Our results indicate that SST cooling is most sensitive to the radius of 64 kt winds (R64) due to its effects on the integrated kinetic energy of the TC and subsequent mixing of the ocean surface layer. It is also found that the correlation between SST cooling induced by the TC and its size is 0.49, which is the highest among all the parameters tested. This suggests that it is extremely important to get TC size correct in order to predict the SST cooling response, which then impacts TC evolution in numerical weather prediction models.

中文翻译：

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热带气旋风半径对海面温度降温的不确定性

热带气旋 (TC) 下的海面温度 (SST) 对其动力学非常重要；因此，了解并准确估计 SST 冷却的幅度至关重要。已有研究探讨了台风平移速度、最大海面风速、海洋热状况和海洋分层对海温的重要影响。但是TC风半径（或统称为TC大小）对SST的影响在很大程度上被忽视了。在这项研究中，我们通过 2014-2018 年北太平洋西部的总共 15,983 个数值模拟来评估风半径不确定性对 SST 冷却的影响。结果显示，使用联合台风预警中心官方预测的风半径会导致 6%–20% 的 SST 冷却误差，使用飓风天气研究和预测 (HWRF) 运行运行的风半径会导致 35%–40% 的 SST 冷却误差模型。我们的结果表明，SST 冷却对 64 kt 风 (R64) 的半径最敏感，因为它会影响 TC 的综合动能和随后的海洋表层混合。还发现TC引起的SST冷却与其大小之间的相关性为0.49，是所有测试参数中最高的。这表明，为了预测 SST 冷却响应，获得正确的 TC 大小非常重要，这会影响数值天气预报模型中的 TC 演化。