Poleward flows in the southern California Current System: Glider observations and numerical simulation
Poleward flows in the southern California Current System: Glider observations and numerical simulation
复制标题
南加州洋流系统中的极向流：滑翔机观测和数值模拟
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
B. Cornuelle
中科院分区：
文献类型：
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作者：
R. Todd;D. Rudnick;M. Mazloff;R. Davis;B. Cornuelle
[1]通过对加州南部海流系统（CCS）连续三年的喷雾滑翔机观测，结合数值模拟，描述了CCS南部向极流的平均值和变率。滑翔机沿着两条跨岸勘测线提供了具有良好的跨岸和时间分辨率的上层海洋观测，而数值模拟则提供了对海洋状况的动态一致的估计。在三个区域观察到持续的向极流动：在Point Conception海岸100 km以内，在南加州湾（SCB）内，以及SCB和圣罗莎海岭（SRR）的近海。在SCB和海上的SRR的流量向极运输超过了点概念的向极运输，这表明向极的流量是不连续的观测线之间的225公里。数值模拟显示，在到达Point Conception之前，与一些转向离岸的极向流一致的测量线之间的离岸运输。SRR近海的极向流是独特的，因为它在深度大于350米时最强，据观察，它向西迁移远离海岸。这种向西传播是绑在西传播的密度异常起源于SCB在春夏上升流季节风应力旋度是最强烈的积极。跨岸波数，频率和相速度的向西传播和跨岸输送的盐度沿着isopycnals的缺乏是一致的第一模态斜压Rossby动力学。
[1] Three years of continuous Spray glider observations in the southern California Current System (CCS) are combined with a numerical simulation to describe the mean and variability of poleward flows in the southern CCS. Gliders provide upper ocean observations with good across-shore and temporal resolution along two across-shore survey lines while the numerical simulation provides a dynamically consistent estimate of the ocean state. Persistent poleward flows are observed in three areas: within 100 km of the coast at Point Conception, within the Southern California Bight (SCB), and offshore of the SCB and the Santa Rosa Ridge (SRR). Poleward transport by the flows within the SCB and offshore of the SRR exceeds the poleward transport off Point Conception, suggesting that the poleward flows are not continuous over the 225 km between observation lines. The numerical simulation shows offshore transport between the survey lines that is consistent with some of the poleward flow turning offshore before reaching Point Conception. The poleward current offshore of the SRR is unique in that it is strongest at depths greater than 350 m and it is observed to migrate westward away from the coast. This westward propagation is tied to westward propagating density anomalies originating in the SCB during the spring-summer upwelling season when wind stress curl is most strongly positive. The across-shore wave number, frequency, and phase speed of the westward propagation and the lack of across-shore transport of salinity along isopycnals are consistent with first-mode baroclinic Rossby dynamics.