Evidence of enhanced turbulent dissipation in the frontogenetic Kuroshio Front thermocline
Evidence of enhanced turbulent dissipation in the frontogenetic Kuroshio Front thermocline
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DOI：
10.1029/2009gl038832
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发表时间：
2009-06-30
影响因子：
5.2
通讯作者：
Doubell, Mark J.
中科院分区：
文献类型：
--
作者：
Nagai, Takeyoshi;Tandon, Amit;Doubell, Mark J.
2008年8月，利用XBT和ADCP微结构剖面仪沿沿着143度观测了黑潮锋生期间黑潮锋气旋侧温跃层中O（10（-8）-10（-7））Wkg（-1）的增强湍流耗散。中心喷流下方混合的涡动扩散系数为O（10（-4）-10（-3））m（2）s（-1）。我们在黑潮中观察到的强湍流混合与以前的现场测量形成鲜明对比，以前的现场测量发现，西部边界流中的小尺度穿环混合保持在通常在开阔洋温跃层中测量的水平。黑潮湍流是由锋生引起的，基于卫星高度计的汇流率估计为O（10（-5））s（-1），这表明海洋锋附近普遍存在从中尺度到微尺度湍流的前向能量级联。引文：永井，T.，A. Tandon，H. Yamazaki和M. J. Doubell（2009），在锋生黑潮锋温跃层中增强湍流耗散的证据，Geophys。Res. Lett.，36，L12609，doi：10.1029/2009GL038832。
Enhanced turbulent dissipation, O(10(-8)-10(-7)) Wkg(-1) in the thermocline on the cyclonic side of the Kuroshio Front was observed during a period of frontogenesis, using a microstructure profiler, XBT and ADCP along 143 degrees E across the Kuroshio Front in August 2008. The eddy diffusivity corresponding to the mixing below the central jet is estimated to be O(10(-4)-10(-3)) m(2) s(-1). The strong turbulent mixing we observed in the Kuroshio is in sharp contrast to previous field measurements which found that small scale diapycnal mixing in western boundary currents remains at levels typically measured in the open ocean thermocline. The turbulence in the Kuroshio is attributed to frontogenesis arising out of an estimated confluence rate of O(10(-5)) s(-1) based on satellite altimeters, suggesting the ubiquity of a forward energy cascade from mesoscale to microscale turbulence near ocean fronts as indicated by recent theoretical studies. Citation: Nagai, T., A. Tandon, H. Yamazaki, and M. J. Doubell (2009), Evidence of enhanced turbulent dissipation in the frontogenetic Kuroshio Front thermocline, Geophys. Res. Lett., 36, L12609, doi:10.1029/2009GL038832.