Study on the Mechanism of Crawling up of the Kuroshio Deep Water in the Continental Slope Area

在坡区附近测得的能量耗散率垂直分布表明，底部混合层的耗散率可能很大，而底部上方的垂直混合应该是剧烈的。底部上方的垂直涡旋扩散系数有时大于10 cm^2s^<-1>。利用大陆斜坡上部系泊的海流仪，考察了大陆斜坡附近内潮的垂直结构。分析认为，随着黑潮通道位置的变化，其结构会发生变化，特别是在斜底上方的层，而在靠近温跃层的中层，大潮期间内潮会加剧。当坡底附近的密度结构接近临界时，可能会发生这种位于底部上方的间歇内潮。人们没有认识到，爬向大陆架断裂带的低温水柱的尖端随着潮流来回摆动。第二层温跃层以上层水和爬行水的垂直振荡为特征，底部混合水的厚度因内部潮汐运动而变化。从停泊在陆架断裂带附近底部上方的海流计获得的当前数据来看，时间尺度超过25小时的平均流量在陆架断裂带附近的底部上方有一个上坡分量，尽管它们在上层有近海分量。这可能是一个证据，表明爬上的低温水应该是由刚好在倾斜底部上方的水流的上坡部分形成的。建立了二维数值模型，研究了坡区附近上坡流的形成过程。数值实验结果表明，当垂直混合时间尺度小于惯性周期时，在陆架断裂周围形成靠近底部的上坡二次流。少

Vertical distribution of the energy dissipation rate measured near the slope region indicated that the dissipation rate could be large in the bottom mixed layer, and the vertical mixing should be vigorous just above the bottom. The vertical eddy diffusivity estimated just above the bottom was sometimes more than 10 cm^2s^<-1>.Vertical structure of internal tides near the continental slope was examined by current meters moored near the upper part of the continental slope. And it was suggested that the structure should varied in dependent with the variation of the location of Kuroshio's passage particularly at the layer just above the sloping bottom, while in the middle layer, near the thermocline it was recognized that the internal tides should be intensified during the spring tide. Such intermittent internal tides just above the bottom may occur when the density structure near the sloping bottom should be near critical.It was not recognized that the tip of the low temperature water mas … More s crawling up to continental shelf break oscillated back and forth accompanied with the tidal current. The second thermocline characterized by the upper and of the crawling up water oscillated vertically, and the thickness of the bottom mixed water varied by means of the internal tidal motions.From the current data obtained by current meters moored just above the bottom near the shelf break, it was shown that the averaged flows with a time scale longer than 25 hours had an up-slope component just above the bottom near the shelf break, though they had offshore component at the upper layers. This may be an evidence that the crawling-up low temperature water should be formed by the up-slope component of the current just above the sloping bottom.Two-dimensional numerical model was developed to examine the formation of the up-slope flow near the slope area. Numerical experiments indicated that up-slope secondary flow near the bottom around the shelf break should be formed when the time scale of vertical mixing is shorter than the inertial period. Less