OBSERVATIONS OF OFFSHORE SHELF-WATER TRANSPORT INDUCED BY A WARM-CORE RING
OBSERVATIONS OF OFFSHORE SHELF-WATER TRANSPORT INDUCED BY A WARM-CORE RING
复制标题
DOI：
10.1016/s0198-0149(11)80007-5
复制
发表时间：
1992-03-01
期刊：
影响因子：
--
通讯作者：
BROWN, OB
中科院分区：
文献类型：
--
作者：
JOYCE, TM;BISHOP, JKB;BROWN, OB
墨西哥湾流暖心环经常被观测到从大陆架带走水，并将大陆架水的细丝输送到大陆坡。1982年6月，“奋进号”考察船在暖心环82 B以东的一个这样的陆架水“拖缆”上做了一个断面，从卫星热成像上可以看到。通过拖缆制作了声学多普勒海流剖面图和重复CTD站。CTD系统还配备了溶解氧传感器和透射仪。我们能够做出一个前所未有的速度和水团结构的架子水丝。观测到的近海速度结构很复杂，速度范围从10到50 cm s-1，温度，在次表层温度最低值，低于8 ℃，表面盐度低于千分之33，悬浮颗粒物和锰含量高，拖缆中心水深达100 m。在不同温度和盐度等级下计算的输送量表明，对于盐度< 35 ppm的水，丝状体中沃茨的总输送量为0.8-0.9 x 10（6）m3 s-1。热成像显示，拖缆没有'缠绕'的环，但平流的环和沉积在墨西哥湾流的近岸边缘。使用不在拖缆中的相邻工作站。但在斜坡水中，作为假定取代上述陆架水数量的水的参考，已经对由于82 B的陆架水的离岸运输而引起的热盐、颗粒、溶解氧和Mn的净交换进行了估计。这些估计表明，暖心环能够引起美国东北海岸外陆架/陆坡水锋的显著交换。
Gulf Stream warm-core rings often are observed to entrain water from the continental shelf and transport filaments of shelf water out over the continental slope. In June 1982 the R.V. Endeavor made a transect through one such shelf-water "streamer" that was seen from satellite thermal imagery to the east of warm-core ring 82B. Acoustic doppler current profiles together with repeated CTD stations were made through the streamer. The CTD system was also equipped with a dissolved oxygen sensor and transmissometer. We were able to make an unprecedented section of velocity and water mass structure of the shelf-water filament. The offshore velocity structure observed was complicated with velocities ranging from 10 to 50 cm s-1, temperatures, in a sub-surface temperature minimum, of less than 8-degrees-C, surface salinities less than 33 parts per thousand, with high levels of suspended particulate matter and manganese, and with shelf-water properties as deep as 100 m in the center of the streamer. Transports calculated in different temperature and salinity classes showed a total volume transport of waters in the filament of 0.8-0.9 x 10(6) m3 s-1 for water with a salinity < 35 parts per thousand. Thermal imagery shows that the streamer was not 'wrapped around' the ring but was advected by the ring and deposited at the inshore edge of the Gulf Stream. Using adjacent stations not in the streamer. but in the Slope Water, as a reference for water that presumably replaced the above amount of shelf water, estimates have been made of the net exchange of heat salt, particulates, dissolved oxygen and Mn due to the offshore transport of shelf water by 82B. These estimates indicate that warm-core rings are capable of inducing significant exchange across the Shelf/Slope Water front off the northeast coast of the U.S.A.