Deep-Current Variability near the Sigsbee Escarpment in the Gulf of Mexico
Deep-Current Variability near the Sigsbee Escarpment in the Gulf of Mexico
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DOI：
10.1175/jpo2998.1
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发表时间：
2007-03
影响因子：
3.5
通讯作者：
P. Hamilton
中科院分区：
文献类型：
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作者：
P. Hamilton
摘要观测深海流，从一个紧密间隔的阵列部署在基地的Sigsbee陡崖，南部的密西西比三角洲，主要是充满活力的，短周期（10天）的地形Rossby波。在2年的时间间隔内，出现了不同的波浪序列，具有不同的特征周期，波长和水平能量分布，通常始于大幅度电流波动的爆发，在接下来的2-3个月内缓慢衰减。两个波列与脱落和向西通过的主要环路电流反气旋，但是，一个事件发生时，上层电流是静止的。后一种波列表明，在2000米水柱中，底陷地形波运动可追踪到距水面300米以内。射线追踪表明，一个可能的源区的短周期波是西侧的扩展环路电流。数据和射线路径表明，通过折射和反射，陡峭的表面。
Abstract Observations of deep currents, from a closely spaced array deployed at the base of the Sigsbee Escarpment, south of the Mississippi Delta, are dominated by energetic, short-period (∼10 days) topographic Rossby waves. Over a 2-yr interval, distinct trains of waves occurred, with differing characteristic periods, wavelengths, and horizontal energy distribution, usually initiated with a burst of large-amplitude current fluctuations that slowly decay over the next 2–3 months. Two of the wave trains were associated with the shedding and westward passage of major Loop Current anticyclones; however, one event occurred when upper-layer currents were quiescent. This latter wave train showed that bottom-trapped topographic wave motions can be traced to within 300 m of the surface in a 2000-m water column. Ray tracing showed that a likely source region of the short-period waves was the west side of an extended Loop Current. The data and ray paths suggest that, through refraction and reflection, the steep es...