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 ~ 12日，在东海陆架坡折附近沿着一个跨陆架剖面上，获得了温、盐、浊度的垂直剖面。在大多数测量站的底部上方检测到高浊度水。在陆坡区的中间层可检测到相对高浊度的水，并沿断面上的等密度面沿着分布，表明高浊度水应在陆架底部正上方侵入黑潮。根据1996年11月的短间距观测资料，发现了陆架区低盐度水入侵黑潮的明显证据。然而，在1996年，低盐度水的起源似乎并不位于陆架底部附近，而是起源于陆架区的表层附近，并且入侵水的浊度没有明显的区别。在黑潮下游5 km处的两个断面上，入侵体的结构变化不大，表明入侵体的沿陆架尺度至少大于10 km。1995年11月，在两天的系泊中，在距底120和60 m处的流速仪上，间歇性地观测到内潮、周期为10 ~ 30 min沿着的短时间尺度内波和短时间尺度湍流脉动。虽然尚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湍流的频繁发生或小尺度内波的破碎产生的。

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.