Surface cooling caused by rare but intense near-inertial wave induced mixing in the tropical Atlantic
Surface cooling caused by rare but intense near-inertial wave induced mixing in the tropical Atlantic
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DOI：
10.1038/s41467-020-17601-x
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发表时间：
2020-07-31
影响因子：
16.6
通讯作者：
Brandt, Peter
中科院分区：
文献类型：
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作者：
Hummels, Rebecca;Dengler, Marcus;Brandt, Peter
热带混合层对近惯性波（NIWs）的直接响应很少被观测到。在这里，我们提出了上层海洋湍流数据，提供了证据表明，在NIW存在的情况下，混合层底部的垂直扩散热通量强烈升高，从而在20小时的连续测量中以244 Wm（-2）的速率冷却混合层。我们调查了强NIW事件的季节性周期，发现尽管它们具有局部间歇性，但它们优先发生在北方夏季，可能与大气非洲东风波的通过有关。我们说明了这些罕见的，但强烈的NIW引起的混合事件的混合层热平衡的影响，突出他们的贡献，海表面温度的季节性演变，并讨论其对生物生产力在热带北大西洋的潜在影响。海洋的热带混合层对近惯性波的反应很少被直接观察到。在这里，作者提出了新的数据，显示强烈升高的垂直扩散热通量在近惯性波的存在下，导致冷却的混合层，特别是在夏季。
The direct response of the tropical mixed layer to near-inertial waves (NIWs) has only rarely been observed. Here, we present upper-ocean turbulence data that provide evidence for a strongly elevated vertical diffusive heat flux across the base of the mixed layer in the presence of a NIW, thereby cooling the mixed layer at a rate of 244Wm(-2) over the 20h of continuous measurements. We investigate the seasonal cycle of strong NIW events and find that despite their local intermittent nature, they occur preferentially during boreal summer, presumably associated with the passage of atmospheric African Easterly Waves. We illustrate the impact of these rare but intense NIW induced mixing events on the mixed layer heat balance, highlight their contribution to the seasonal evolution of sea surface temperature, and discuss their potential impact on biological productivity in the tropical North Atlantic. How the tropical mixed layer of the ocean reacts to near-inertial waves has rarely been observed directly. Here, the authors present new data that shows strongly elevated vertical diffusive heat flux in the presence of near-inertial waves, causing a cooling of the mixed layer that is particularly strong in summer.