The Effect of Double Diffusive Convention in the Mixing region at the oceanic front

1. 分析了居潮锋区CTD、XCTD和ADCP的详细数据。(1)逆温层分布频繁，由北向北延伸。热/咸水团和冷/淡水团在垂直方向上交替堆积，表明双扩散对流活跃。(2)近海区逆温层多于近岸区。强烈的逆温现象主要发生在与黑潮直接接触的北部地区。(3)将中性面分析应用于黑潮伸展期的尾潮地区，揭示了环结和盐指对流在北太平洋中间水（NPIW）的改变过程中所起的重要作用。为了了解极地地区的深对流过程，研究了热压对深对流发生的影响。(1)随着热压效应的引入，即使在流体层稳定分层时也会出现深部对流羽流。(2)在上述情况下引入双扩散效应时，双扩散抑制了对流的发生。对双扩散锁交换流动进行了数值研究，结果表明，双扩散对流的引入抑制了通常出现在界面处的开尔文-亥姆霍兹不稳定性。

1. Detailed CTD, XCTD and ADCP data at the Oyashio Frontal region were analyzed.(1)Temperature inversion layers were frequently observed as the Oyashio Water mass extended from north. Hot/salty and cold/fresh water masses were piled up alternatively in the vertical direction suggesting the active double diffusive convection.(2)Temperature inversion layers were observed more at the offshore region than the coastal region. And the strong temperature inversions were observed more at the northern area where the Oyashio and the Kuroshio waters were contacted directly.(3) Neutral surface analysis was applied for the Oyashio region to the Kuroshio Extension, which reveals the important role of cabbeling and salt finger convection to the modification process of the Northa Pacific Intermediate Water (NPIW).2. To understand the deep convection process at the polar region, thermobaric effect on the onset of deep convection was conducted.(1) With the introduction of thermobaric effect, deep convective plumes were occurred even when the fluid layer was stably stratified.(2) As for the case when the double diffusive effect is introduced to the above case, the onset of convection was suppressed by the double diffusion.3. Double diffusive lock exchange flow is investigated numerically, and as a result, Kelvin-Helmholtz instability usually appeared at the interface was suppressed by the introduction of double diffusive convection.