The seasonal circulation and volume transport on the northwest European continental shelf: A fine‐resolution model study
The seasonal circulation and volume transport on the northwest European continental shelf: A fine‐resolution model study
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欧洲西北部大陆架的季节性环流和体积输送：精细分辨率模型研究
DOI：
10.1029/2006jc004034
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发表时间：
2008
影响因子：
--
通讯作者：
R. Proctor
中科院分区：
文献类型：
--
作者：
J. Holt;R. Proctor
本文利用大陆架宽尺度和亚罗斯比半径分辨率（类似于 1.8 公里）的第一年密度演化模拟研究了西北欧大陆架的环流。进行了一系列数值实验来区分流的风驱动、密度驱动和海洋驱动分量。这些表明，虽然所有组成部分在全年中都发挥着作用，但密度驱动的组成部分在夏季和秋季尤为重要。密度场的时间演化对陆架范围内体积运输的季节性变化做出了重大贡献，并且在方向上是持续的；而风驱动的体积运输作用的时间尺度要短得多，并且方向变化更大。论证了海洋强迫的重要性，代表潮汐残余和大规模海洋海平面（压力）变化；这种强迫推动了全年环流的很大一部分。 2001 年夏天部署的 26 个卫星跟踪漂流器用于直接验证模型水流。当对大约 40 天进行平均时，模型当前速度的准确度约为 46%，但往往太慢。夏季流量通量与文献中的估计值进行比较，显示出良好的一致性，尽管有人认为北海流入量被高估了。与用于边界条件的较粗分辨率模型的比较证明了精细分辨率对锋流细节的重要性，以及对这些区域的交换过程和生物活动建模的影响
In this paper the circulation of the northwest European continental shelf is investigated using the first year-long density-evolving simulation at shelf wide scales and sub-Rossby Radius resolution (similar to 1.8 km). A series of numerical experiments are conducted to distinguish between the wind-, density-, and oceanic-driven components of the flow. These demonstrate that, while all components have a role throughout the year, the density- driven component is particularly important during the summer and autumn months. The time evolution of the density field makes a significant contribution to the seasonal variation of volume transport on shelf wide scales and is persistent in direction; whereas the wind- driven volume transport acts on much shorter timescales and is more variable in direction. The importance of the oceanic forcing is demonstrated, representing tidal residuals and large-scale oceanic sea level (pressure) variation; this forcing drives a substantial component of the circulation throughout the year. Twenty six satellite tracked drifters deployed in the summer of 2001 are used for a direct validation of the model currents. The model current speeds are found to be accurate to similar to 46% when averaged over similar to 40 d, but tend to be too slow. The summer volume fluxes are compared with estimates in the literature showing good agreement, although there is a suggestion that the North Sea inflows are overestimated. Comparisons with the coarser resolution model used for boundary conditions demonstrate the importance of fine-resolution to the details of the frontal currents with consequences for modeling exchange processes and biological activity in these regions