Assessing the oceanic control on the amplitude of sea surface cooling induced by tropical cyclones
Assessing the oceanic control on the amplitude of sea surface cooling induced by tropical cyclones
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DOI：
10.1029/2011jc007705
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发表时间：
2012-05
影响因子：
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通讯作者：
E. Vincent;M. Lengaigne;J. Vialard;G. Madec;N. Jourdain;S. Masson
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文献类型：
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作者：
E. Vincent;M. Lengaigne;J. Vialard;G. Madec;N. Jourdain;S. Masson
2011 年 10 月 24 日收到； 2012 年 3 月 28 日修订； 2012 年 3 月 30 日接受； 2012 年 5 月 15 日发表。 [1] 热带气旋 (TC) 会导致海面变冷，从而对其强度产生负面影响。先前的研究表明，降温幅度取决于海洋条件和热带气旋特征，但这种海洋控制的记录很少。我们使用全球海洋模型实验研究了海洋对热带气旋引起的冷却的影响，该实验真实地采样了过去 30 年海洋对 3,000 多个热带气旋的响应。我们得出了一个物理基础的海洋参数，即冷却抑制指数（CI），它测量通过垂直混合冷却海洋表面所需的潜在能量输入，从而解释了风暴前的上层海洋层结对TC引起的冷却的阻力。大气控制是使用风力指数（WPi）来描述的，风力指数是TC传递到海洋的动能的代表，它考虑了最大风速和平移速度的影响。冷却幅度几乎随 WPi 线性增加。然而，对于给定的 WPi，冷却幅度可能会变化一个数量级：强风能输入可能导致 0.5°C 或 5°C 冷却，具体取决于海洋背景状态。除了风能输入之外，使用 CI 等海洋参数可将冷尾流振幅的统计后报改善约 40%。因此，根据通过垂直混合冷却海洋表面所需的势能推导海洋参数是在热带气旋研究中更好地解释海洋特征的一种有前途的方法。
Received 24 October 2011; revised 28 March 2012; accepted 30 March 2012; published 15 May 2012. [1] Tropical cyclones (TCs) induce sea surface cooling that feeds back negatively on their intensity. Previous studies indicate that the cooling magnitude depends on oceanic conditions as well as TC characteristics, but this oceanic control has been poorly documented. We investigate the oceanic influence on TC-induced cooling using a global ocean model experiment that realistically samples the ocean response to more than 3,000 TCs over the last 30 years. We derive a physically grounded oceanic parameter, the Cooling Inhibition index (CI), which measures the potential energy input required to cool the ocean surface through vertical mixing, and hence accounts for the pre-storm upper-ocean stratification resistance to TC-induced cooling. The atmospheric control is described using the wind power index (WPi), a proxy of the kinetic energy transferred to the ocean by a TC, which accounts for both the effects of maximum winds and translation speed. The cooling amplitude increases almost linearly with WPi. For a given WPi, the cooling amplitude can however vary by an order of magnitude: a strong wind energy input can either result in a 0.5 � Co r 5 � C cooling, depending on oceanic background state. Using an oceanic parameter such as CI in addition to wind energy input improves statistical hindcasts of the cold wake amplitude by � 40%. Deriving an oceanic parameter based on the potential energy required to cool the ocean surface through vertical mixing is thus a promising way to better account for ocean characteristics in TCs studies.