Physical dynamics on the continental shelf off southwestern Ireland and their influence on coastal phytoplankton blooms
Physical dynamics on the continental shelf off southwestern Ireland and their influence on coastal phytoplankton blooms
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DOI：
10.1016/s0278-4343(98)00017-x
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发表时间：
1998-07-01
影响因子：
2.3
通讯作者：
McMahon, T
中科院分区：
文献类型：
--
作者：
Raine, R;McMahon, T
记录了1992年至1995年期间爱尔兰西南部陆架沃茨的物理、化学和生物特征的分布。分隔海岸和海洋水域的盐锋（爱尔兰大陆架锋; ISF）的位置有一个水平的运动尺度，与锋到海岸线的距离相当（约200米）。30公里）。在该地区部署了120天的海流测量显示，锋面近岸有8 cm s（-1）的残余西北流（325度），离岸有3.5 cm s（-1）的东南流（160度）。浮力驱动的海岸流的ISF近岸的风向进行修改。在从西南象限延伸的风期间，观察到一个与测得的剩余流量大小相似的东南方向的平衡风驱动流。在这种情况下，以色列安全部队逼近海岸线。东风导致爱尔兰西南部附近出现强烈的顺时针沿岸气流（风速为-20厘米），锋面位于更远的近海。因此，在盛行的西南风下，西北部凯尔特海的水倾向于变得孤立，因此，密度跃层以下的溶解氧水平在夏末明显减少（65-70%饱和度）。与此同时，高浓度的甲藻与密度跃层经常记录在这个水。这些甲藻群落平流走向和进入海湾西南部的爱尔兰时，沿海电流近岸的ISF流动，由于风向的变化，这往往导致变色的水，或“赤潮”，沿着海岸。(C)1998爱思唯尔科技有限公司版权所有。
Distributions of physical, chemical and biological characteristics were recorded for shelf waters off southwestern Ireland between 1992 and 1995. The location of a haline front (the Irish Shelf Front; ISF) separating coastal and oceanic water had a horizontal scale of movement comparable to the distance of the front from the coastline (ca. 30 km). Current measurements from deployments of up to 120 days in the region revealed a residual northwestwards (325 degrees) flow of 8 cm s(-1) inshore of the front and a southeastwards flow (160 degrees) of 3.5 cm s(-1) offshore. The buoyancy-driven coastal flow inshore of the ISF was modified by wind direction. During periods of extended winds from the southwest quadrant a counterbalancing wind-driven flow to the southeast of similar magnitude to the measured residual flow was observed. Under these conditions the ISF approached the coastline. Winds blowing from the east resulted in a strong (20 cm s(-1))clockwise coastal flow around southwestern Ireland and the front was found further offshore. Thus, under prevailing southwesterly winds, water in the northwestern Celtic Sea tended to become isolated and, as a result, dissolved oxygen levels below the pycnocline became markedly reduced (65-70% saturation) towards late summer. At the same time high concentrations of dinoflagellates associated with the pycnocline were frequently recorded in this water. These dinoflagellate communities were advected towards and into the bays of southwestern Ireland when the coastal current inshore of the ISF flowed as a result of changes in wind direction; this often resulted in discoloured water, or 'red tides', along the shore. (C) 1998 Elsevier Science Ltd. All rights reserved.