Study on the Boundary Mixing and Intrusion of Shelf Water into the Intermediate Layr of the Kuroshio around the Continental Shelf Break

1995年11月10日至12日，沿中国东海陆架断裂附近的陆架剖面获得了温度、盐度和浊度的垂直剖面。在大多数测量站的底部上方都检测到高浊度的水。在斜坡区的中层可以检测到较高的浊度水，在剖面上沿等轴面分布，表明陆架底部正上方的高浊度水应该侵入黑潮。从1996年11月在观测点的短间距观测中发现，来自陆架区的低盐度水入侵黑潮的明显证据。然而，1996年低盐度水的来源似乎不在陆架底部附近，而是在陆架区表层附近，侵入水的浊度没有明显差异。在黑潮下游方向相距5英里的两段之间，侵入的结构变化不大，这表明沿陆架的规模至少将大于10公里。另一项利用停泊在陆架周围250m水深的海流计测量发现了几种不同时间尺度的内波。1995年11月，在取样间隔为1分钟的两天系泊中，海流计在海底以上120米和60米处间歇性地观测到内潮、短时间尺度内波和较短时间尺度的湍流起伏。虽然还不清楚内波与湍流或垂直混合的关系，但上述入侵可能是由于湍流的频繁发生或小尺度内波的破裂而产生的。

During 10 to 12 November, 1995, vertical profiles of temperature, salinity and turbidity were obtained along a cross-shelf section near the continental shelf break in the East China Sea. High turbidity water was detected just above the bottom at most of the measuring stations. And relatively high turbidity water could be detected in the intermediate layr of the slope region, which distributed along an isopycnal surface on the section, suggesting that the high turbidity water just above the bottom of the shelf should intrude into the Kuroshio. From the observations with short spacing in observation points in November, 1996, it was found that distinct evidence of intrusion of low salinity water from the shelf area into the Kuroshio. However, in 1996, origin of the low salinity water seemed to not be located near the bottom of the shelf but originated around surface layr in the shelf region, and there were no significant distinction in turbidity in the intruded water. The structure of the intrusion did not change so much between two sections with 5 miles distance in down stream direction of the Kuroshio, which indicated that the along-shelf scale of the intrusion would be larger than 10 km at least.Another measurements with current meters moored at 250m water depth around the shelf break detected internal waves with several kinds of time scale. In two days mooring with 1 minute sampling interval in November 1995, internal tide, short time scale internal waves with the several periods from 10 to 30minutes along with shorter time scale turbulent fluctuations were seen intermittently from current meters at 120 and 60m above the bottom. Although it was not clear how the internal waves related to turbulence or vertical mixing, above mentioned intrusion could be generated by frequent occurrence of turbulence or breaking of small scale internal waves.