The effect of wind on the dispersal of the Hudson River plume
The effect of wind on the dispersal of the Hudson River plume
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DOI：
10.1175/jpo3081.1
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发表时间：
2007-07-01
影响因子：
3.5
通讯作者：
Wilkin, John L.
中科院分区：
文献类型：
--
作者：
Choi, Byoung-Ju;Wilkin, John L.
利用三维模式研究了哈德逊河烟羽在理想风强迫作用下的扩散。该模型域包括哈德逊河及其河口，具有逼真的海岸线和纽约湾的海底地形。稳定的低河流流量典型的平均条件和高流量的事件代表的春天的淡水。没有风强迫的羽流形成一个向南的沿海被困电流在低河流排放和一个大的再循环膨胀的低盐度水在高排放事件。风影响通过河口的淡水输出，这是羽流进入中大西洋湾内大陆架沃茨的轨迹，以及淡水向下游排放的速度。扩散轨迹也受到纽约湾顶点海岸线的特殊地理的影响。向北的风导致先前形成的沿海被困羽流离岸位移，并驱动一个新的羽流沿着长岛海岸。南风引起强烈的海岸急流，有效地将淡水排向南方。东风有助于淡水从河口输出，并有利于淡水在拉里坦湾口外的再循环凸起中的积累。向西风延迟了拉里坦湾的淡水输出。模拟羽流的动量平衡表明，浮力和风力在很大程度上决定了水平淡水扩散的模式，包括淡水在环境中的扩散，更多的盐水和隆起的形成。
The dispersal of the Hudson River plume in response to idealized wind forcing is studied using a three-dimensional model. The model domain includes the Hudson River and its estuary, with a realistic coastline and bottom topography of the New York Bight. Steady low river discharge typical of mean conditions and a high-discharge event representative of the spring freshet are considered. Without wind forcing the plume forms a southward coastally trapped current at low river discharge and a large recirculating bulge of low-salinity water during a high-discharge event. Winds affect the freshwater export through the mouth of the estuary, which is the trajectory the plume takes upon entering the waters of the Mid-Atlantic Bight inner shelf, and the rate at which freshwater drains downstream. The dispersal trajectory is also influenced by the particular geography of the coastline in the apex of the New York Bight. Northward wind causes offshore displacement of a previously formed coastally trapped plume and drives a new plume along the Long Island coast. Southward wind induces a strong coastal jet that efficiently drains freshwater to the south. Eastward wind aids freshwater export from the estuary and favors the accumulation of freshwater in the recirculating bulge outside the mouth of Raritan Bay. Westward wind delays freshwater export from Raritan Bay. The momentum balance of the modeled plume shows that buoyancy and wind forces largely determine the pattern of horizontal freshwater dispersal, including the spreading of freshwater over ambient, more saline water and the bulge formation.