Wind Power on Oceanic Near-Inertial Oscillations in the Global Ocean Estimated From Surface Drifters
Wind Power on Oceanic Near-Inertial Oscillations in the Global Ocean Estimated From Surface Drifters
复制标题
根据海面漂流物估计风力发电对全球海洋近惯性振荡的影响
DOI：
10.1029/2018gl081712
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发表时间：
2019-03-16
影响因子：
5.2
通讯作者：
Wu, Lixin
中科院分区：
文献类型：
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作者：
Liu, Yongzheng;Jing, Zhao;Wu, Lixin
海洋近惯性振荡的风力发电被认为在提供海洋内的湍动混合中起着重要作用。然而，它们的全球分布和大小尚未根据观测结果进行量化。在这项研究中，我们使用来自地表漂流者的每小时洋流记录，结合卫星获得的地表风测量数据，计算1993-2016年全球近惯性风力。在南纬60度到北纬60度之间，综合的气候性近惯性风电估计为0.3-0.6TW。在冬季，能量通量最强的区域是30-60度纬带，这是高能风暴活动的结果。洋流对风应力的影响对全球漂移者近惯性风力的估计有显著影响。如果忽略这一影响，当地的近惯性风力发电将被高估25-120%，其全球平均值将被高估60%。近惯性波段的风应力波动会共振地影响地面混合层的近惯性振荡。这些由风产生的nio向下辐射到海洋内部，将它们的能量转移到小尺度上，并最终破裂，为温跃层和深海中的潜流湍流混合提供能量。近二十年来，基于数值模型对全球近惯性风力发电进行了广泛的研究。然而，各研究的估计值差异很大（0.3-1.5TW）。如此大的范围使模拟近惯性风力的模型的有效性受到质疑。在海洋环流模式中，nio对准周期湍流混合及其参数化的贡献也存在不确定性。因此，在观测的基础上获得全球近惯性风电的基准是十分必要的。在这项研究中，我们评估了基于漂移和卫星测量风的全球近惯性风力。在南纬60度到北纬60度之间，综合的气候性近惯性风电估计为0.3-0.6TW。研究发现，海流对风应力的印记对近惯性风力的估计有显著影响。忽视这一影响会导致全球近惯性风力发电高估60%，局部高估25-120%。
Wind power on oceanic near-inertial oscillations is thought to play an important role in furnishing the diapycnal mixing in the ocean. Yet their global distribution and magnitude have not been quantified based on observations. In this study, we use hourly ocean current records derived from surface drifters to compute the global near-inertial wind power during 1993-2016, with a combination of surface wind measurements obtained from satellites. The climatological near-inertial wind power integrated between 60 degrees S and 60 degrees N is estimated to be 0.3-0.6TW. The strongest energy flux occurs in the 30-60 degrees latitude band during the winter season as a result of energetic storm activities. Ocean current imprint on wind stress has a significant impact on the estimated global near-inertial wind power from drifters. Neglecting this imprint overestimates the near-inertial wind power locally by 25-120% and its global mean value by 60%.Plain Language Summary Wind stress fluctuations in the near-inertial band can resonantly force near-inertial oscillations (NIOs) in the surface mixed layer. These wind-generated NIOs radiate downwards into the ocean interior, transfer their energy to small scales, and eventually break, providing energy to furnish the diapycnal turbulent mixing in the thermocline and deep ocean. In the past two decades, the global near-inertial wind power has been extensively studied based on numerical models. However, the estimated values differ significantly (0.3-1.5TW) among studies. Such a great range throws doubts on the validity of the model simulated near-inertial wind power. It also causes uncertainties in the contribution of NIOs to diapycnal turbulent mixing and their parametrizations in ocean general circulation models. Therefore, it is essential to obtain a benchmark for global near-inertial wind power based on observations. In this study, we evaluate the global near-inertial wind power based on drifters and satellite-measured winds. The climatological near-inertial wind power integrated between 60 degrees S and 60 degrees N is estimated to be 0.3-0.6TW. It is found that the ocean current imprint on wind stress has a significant impact on the estimated near-inertial wind power. Neglecting this imprint leads to overestimation of near-inertial wind power globally by 60% and locally by 25-120%.