The Impact of Rain on Ocean Surface Waves and Currents
The Impact of Rain on Ocean Surface Waves and Currents
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DOI：
10.1029/2020gl087287
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发表时间：
2020-04-16
影响因子：
5.2
通讯作者：
Zappa, Christopher J.
中科院分区：
文献类型：
--
作者：
Laxague, Nathan J. M.;Zappa, Christopher J.
降水是地球大气和海洋相互作用的重要组成部分，它改变了海气动量、热量和气体的通量。有假设认为，降雨对海面重力波的抑制和厘米尺度波的增强会改变海气动量通量的性质，导致近地面流的增加。在这里，我们使用实地观测来描述这种影响，并测量极近地表电流对降雨的响应。暴雨时产生表面粗糙环波，较长的重力波被抑制；紧接着，近地表洋流的强度随着风力的增强而增加，但随着降雨的减弱和长波的恢复而减弱。这些首次的野外观测表明，雨水减少了海浪的阻力，有利于切向应力，从而导致海面附近的水流加速。众所周知，雨是大气-海洋相互作用的重要组成部分。然而，在地球海洋中，短尺度波浪和非常近表面的海流对降水的具体响应尚未得到描述。我们观察到，降雨抑制长波，形成厘米尺度的环波。这种变化促进了电流的加速，随着雨的消退，电流停止，有利于更长的波的增长。这是首次在地球上真正的海洋中观察到这种现象。
Precipitation is an important component of the interaction between Earth's atmosphere and oceans, modifying air-sea fluxes of momentum, heat, and gas. It has been hypothesized that rain's suppression of ocean surface gravity waves and centimeter-scale wave enhancement should alter the nature of air-sea momentum flux, resulting in increased near-surface current. Here, we use field observations to describe this impact and measure the very near-surface current response to rainfall. During heavy rain, surface-roughening ring waves were generated and longer gravity waves were suppressed; immediately following, the magnitude of the near-surface current increased in response to wind forcing but died as the rain subsided and long waves recovered. These first-of-their-kind field observations indicate that rain reduces ocean wave form drag in favor of tangential stress, resulting in the acceleration of current near the sea surface.Plain Language Summary Rain is known to be an important component of atmosphere-ocean interactions. However, the specific response of short-scale waves and very near-surface current to precipitation has not yet been described in the Earth's ocean. We observe that rainfall suppresses long waves and grows centimeter-scale ring waves. This alteration facilitates the acceleration of current, which ceases in favor of longer wave growth as the rain subsides. This is the first observation of this phenomenon in the Earth's real ocean.