During the TOGA COARE rich horizontal temperature and salinity variability of the near-surface layer of the ocean in the western Pacific warm pool was observed. High-resolution measurements were made by probes mounted on the bow of the vessel in an undisturbed region at ~1.7-m depth during four COARE cruises of the R/V Moana Wave. The authors observed several tens of cases of periodic sharp frontal interfaces of width 1– 100 m and separation 0.2–60 km. The sharp frontal interfaces were often found in frontal regions and on the periphery of freshwater puddles. Maneuvers of the ship were conducted to determine the spatial orientation of a sharp frontal interface. The interfaces revealed anisotropy with respect to the wind direction. They were most sharp when the wind stress had a component along the buoyant spreading of the front. A possible origin of the sharp frontal interfaces is discussed. These interfaces may develop by nonlinear evolution of long-wave disturbances on the near-surface pycnocline that is often observed in the warm pool area. A shallow-water model may describe some features of the observations. A dimensionless number of the Reynolds type is a criterion of transition from wave train solution to dissipative shock-wave structure. The model predicts spatial anisotropy depending on the relative angle between the wind stress and horizontal density gradient.
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机译:在TOGA COARE期间,观测到了西太平洋暖池中海洋近表层的丰富水平温度和盐度变化。高分辨率测量是通过在R / V Moana Wave的四次COARE航行中,将探头安装在未受干扰区域的船首上,深度约为1.7 m的条件下进行的。作者观察到数十种周期性的锋利的正面界面,其宽度为1-100 m,间隔为0.2-60 km。锋利的额叶界面经常出现在额叶区域和淡水水坑的外围。进行船舶操纵以确定锋利的正面接口的空间方向。界面显示出相对于风向的各向异性。当风的应力沿着前部的浮力散布时,它们最锐利。讨论了锋利的正面接口的可能来源。这些界面可能是由于近地表斜线的长波扰动的非线性演化而形成的,这种现象通常在暖池区中观察到。浅水模型可能描述了观测的某些特征。雷诺类型的无量纲数是从波列解到耗散冲击波结构过渡的标准。该模型根据风应力和水平密度梯度之间的相对角度来预测空间各向异性。
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