Metrics of hurricane-ocean interaction: vertically-integrated or vertically-averaged ocean temperature?
Metrics of hurricane-ocean interaction: vertically-integrated or vertically-averaged ocean temperature?
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DOI：
10.5194/os-5-351-2009
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发表时间：
2009-09
期刊：
影响因子：
3.2
通讯作者：
J. Price
中科院分区：
文献类型：
--
作者：
J. Price
抽象。在飓风-海洋相互作用中，海洋热场通常用一个称为上层海洋热含量（OHC）的度量来表示，即海洋温度超过26°C的垂直积分。OHC的高值已被证明有助于识别特别有利于飓风强化的海洋区域。然而，这里有人认为，海洋热场的一个更直接和强大的度量可以提供的垂直平均温度。在最简单的版本中，被称为T 100，平均值是从表面到100米，这是3级飓风垂直混合的典型深度。OHC和T 100在OHC的高范围（≥75 kJ cm−2）的深海开阔洋上有很好的相关性。它们在OHC的低范围内（≤50 kJ cm−2）相关性很差，部分原因是在凉爽的海洋区域（≤26°C）进行评估时，OHC会退化。在浅大陆架上，OHC和T 100也可能有质的不同：无论海洋温度如何，OHC通常都表示相对较低的值，而T 100在温暖和上升流中性或负的大陆架上将呈现高值。仅就海洋热场而言，这些温暖的浅大陆架似乎与温暖的深海地区一样有利于飓风的增强。
Abstract. The ocean thermal field is often represented in hurricane-ocean interaction by a metric termed upper Ocean Heat Content (OHC), the vertical integral of ocean temperature in excess of 26°C. High values of OHC have proven useful for identifying ocean regions that are especially favorable for hurricane intensification. Nevertheless, it is argued here that a more direct and robust metric of the ocean thermal field may be afforded by a vertical average of temperature. In the simplest version, dubbed T 100 , the averaging is from the surface to 100 m, a typical depth of vertical mixing by a category 3 hurricane. OHC and T 100 are well correlated over the deep open ocean in the high range of OHC, ≥75 kJ cm−2. They are poorly correlated in the low range of OHC, ≤50 kJ cm−2, in part because OHC is degenerate when evaluated on cool ocean regions, ≤26°C. OHC and T 100 can be qualitatively different also over shallow continental shelves: OHC will generally indicate comparatively low values regardless of the ocean temperature, while T 100 will take on high values over a shelf that is warm and upwelling neutral or negative. In so far as the ocean thermal field alone is concerned, these warm, shallow continental shelves would appear to be as favorable for hurricane intensification as are warm, deep ocean regions.