Seasonal changes in the tropical Atlantic circulation: Observation and simulation of the Guinea Dome
Seasonal changes in the tropical Atlantic circulation: Observation and simulation of the Guinea Dome
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DOI：
10.1029/91jc02501
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发表时间：
1992-01
影响因子：
--
通讯作者：
G. Siedler;N. Zangenberg;R. Onken;A. Morlière
中科院分区：
文献类型：
--
作者：
G. Siedler;N. Zangenberg;R. Onken;A. Morlière
几内亚圆顶是热脊东侧的一个永久的、准静止的特征，纬向延伸穿过热带北大西洋。穹顶是与北赤道流、北赤道逆流和北赤道潜流有关的大尺度近地表流场的一部分。本文结合历史资料和最近获得的水文资料，研究了圆顶附近的温盐构造和地转流场。结果表明，几内亚巨蛋全年存在于亚温跃层和温跃层中，具有相应的气旋式地转流，其垂直结构、水平范围和位置均发生季节性变化。然后将观测结果与热带大西洋一般环流模式的模拟结果进行比较。一个由观测到的每月风强迫的7年模拟被运行来计算每月的气候学。该模型充分模拟了几内亚巨丘的结构、流场和季节变化。
The Guinea Dome is a permanent, quasi-stationary feature on the eastern side of the thermal ridge extending zonally across the tropical North Atlantic. The dome is a part of the large-scale near-surface flow fields associated with the North Equatorial Current, the North Equatorial Countercurrent and the North Equatorial Undercurrent. In the present study, historical and recently obtained hydrographic data are combined to investigate the thermohaline structure and geostrophic flow field in the vicinity of the dome. It is shown that the Guinea Dome exists throughout the year both in subthermocline and thermocline layers, that it has a corresponding cyclonic geostrophic flow, and that seasonal changes occur with respect to its vertical structure, horizontal extent, and position. The observational results are then compared with simulations from a general circulation model of the tropical Atlantic. A seven-year simulation forced by observed monthly winds is run to compute a monthly climatology. The model adequately simulates the Guinea Dome with respect to its structure, flow field, and seasonal variability.