The Surface Velocity Structure of the Florida Current in a Jet Coordinate Frame: FLORIDA CURRENT SURFACE JET STRUCTURE
The Surface Velocity Structure of the Florida Current in a Jet Coordinate Frame: FLORIDA CURRENT SURFACE JET STRUCTURE
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喷流坐标系中佛罗里达洋流的表面速度结构：佛罗里达洋流表面喷流结构
DOI：
10.1002/2017jc013286
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Johns, William E.
中科院分区：
文献类型：
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作者：
Archer, Matthew R.;Shay, Lynn K.;Johns, William E.
利用高频雷达海流测量研究了25°和26°N之间的佛罗里达海流的结构和变化，以提供迄今为止最详细的表面急流视图。进行了二维射流坐标分析，以确定射流在时间上的横向位移（蜿蜒），以及2年期间（2005-2006）的相关结构变化。在喷流坐标系中，核心速度在阵列中心纬度（25.4°N）的中值为160 cm s− 1，标准差（STD）为35 cm s−1。喷流以3-30天的时间尺度蜿蜒，STD为8 km，下游阶段速度为1080 km d−1。在一个固定的（地理）参考系中计算的涡动动能中，弯曲占到45%。核心速度，宽度，和剪切经历相同的占主导地位的3-30天的变化，加上一个年度的周期，符合季节性的沿岸风应力。25.4°N的急流输送与27°N的流量输送表现出不同的季节性，很可能是由西北普罗维登斯海峡的输入驱动的。核心速度与迈阿密海平面波动成反比，例如40 cm s− 1的减速与海平面上升10 cm有关，尽管海平面与急流弯曲或宽度没有相关性。这种准确的量化佛罗里达电流的变化是至关重要的，以了解和预测未来的变化，在北大西洋的气候系统，以及当地的影响沿海环流和海平面变化沿着南佛罗里达的海岸线。
The structure and variability of the Florida Current between 25° and 26°N are investigated using HF radar ocean current measurements to provide the most detailed view of the surface jet to date. A 2‐D jet coordinate analysis is performed to define lateral displacements of the jet in time (meandering), and associated structural variations over a 2 year period (2005–2006). In the jet coordinate frame, core speed has a median value of ∼160 cm s−1at the central latitude of the array (25.4°N), with a standard deviation (STD) of 35 cm s−1. The jet meanders at timescales of 3–30 days, with a STD of 8 km, and a downstream phase speed of ∼80 km d−1. Meandering accounts for ∼45% of eddy kinetic energy computed in a fixed (geographical) reference frame. Core speed, width, and shear undergo the same dominant 3–30 day variability, plus an annual cycle that matches seasonality of alongshore wind stress. Jet transport at 25.4°N exhibits a different seasonality to volume transport at 27°N, most likely driven by input from the Northwest Providence Channel. Core speed correlates inversely with Miami sea level fluctuations such that a 40 cm s−1deceleration is associated with a ∼10 cm elevation in sea level, although there is no correlation of sea level to jet meandering or width. Such accurate quantification of the Florida Current's variability is critical to understand and forecast future changes in the climate system of the North Atlantic, as well as local impacts on coastal circulation and sea level variability along south Florida's coastline.