The interaction between atmospheres and oceans plays an important role in the global climate. In a field experiment of atmospheric flows over the Gulf Stream, when the wind blew from the cold water to the warm water, we observed a near‐surface jet over the warm water. We then conducted direct numerical simulations and large‐eddy simulations of atmospheric turbulence in the vicinity of the front and captured the near‐surface jet in simulations for the first time. Analyses of the data obtained from the high‐resolution three‐dimensional simulations revealed the dominant generation mechanisms of the near‐surface jet, which are the strong vertical mixing by the enhanced streamwise rolls and the mean downward motion. Around the near‐surface jet, the magnitude of the negatively valued Richardson number significantly increases, indicating the dominance of buoyancy effects in the flow dynamics there. The development of the near‐surface jet suggests that the Monin‐Obukhov similarity theory (MOST) needs to be modified in representing marine atmospheric boundary layers over sea surface temperature fronts.

中文翻译：

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海洋温度前沿大气表面层近地表射流的数值研究

大气与海洋之间的相互作用在全球气候中起着重要作用。在海湾流上方的大气流动的野外实验中，当风从冷水吹向温水时，我们观察到了在暖水上方的近地表射流。然后，我们在前部附近进行了大气湍流的直接数值模拟和大涡模拟，并首次在模拟中捕获了近地表射流。对从高分辨率三维模拟中获得的数据进行的分析揭示了近地表射流的主要生成机制，即增强的水流滚流和垂直向下运动引起的强垂直混合。在近地表射流附近，负值的理查森数的大小显着增加，表明浮力效应在该处的流动动力学中占主导地位。近地表射流的发展表明，Monin-Obukhov相似性理论（MOST）需要进行修改，以表示海面温度前沿上的海洋大气边界层。