Wind stress forcing of the North Sea 'pole tide'
Wind stress forcing of the North Sea 'pole tide'
复制标题
北海“极潮”的风应力强迫
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
A. Au
中科院分区：
文献类型：
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作者：
W. P. O'connor;B. Chao;D. Zheng;A. Au
我们使用具有现实地理和水深测量的正压海洋模型对北海海平面变化的风强迫进行了数值模拟，以检查14个月的“极潮”的强迫，这是已知沿着丹麦-荷兰海岸非常大。模拟输入是美国国家环境预报中心（NCEP）再分析的1958 - 1997年40年期间的月平均地面风应力场。海洋模型输出的海平面响应，然后与10个沿海验潮记录从永久服务平均海平面（PSMSL）在同一时期。除强的季节变化外，还存在几个显著的近7年、3年、14个月、9个月和6.5个月的准周期。相关性和谱分析显示，模型输出与观测值之间存在显着的一致性，特别是在14个月或钱德勒周期带中。后者表明，在北海沿着丹麦-荷兰海岸发现的增强极潮实际上是对风应力强迫的海岸设置响应，周期约为14个月。我们发现没有必要援引地球物理解释，涉及共振增强极潮在北海解释的意见。
SUMMARY We conduct numerical simulations of the wind forcing of sea level variations in the North Sea using a barotropic ocean model with realistic geography and bathymetry to examine the forcing of the 14 month ‘pole tide’, which is known to be anomalously large along the Denmark‐Netherlands coast. The simulation input is the monthly mean surface wind stress field from the National Centers for Environmental Prediction (NCEP) reanalysis for the 40 year period 1958‐1997. The ocean model output sea level response is then compared with 10 coastal tide gauge records from the Permanent Service for Mean Sea Level (PSMSL) over the same period of time. Besides the strong seasonal variations, several prominent quasi-periodicities exist near 7 years, 3 years, 14 months, 9 months and 6.5 months. Correlations and spectral analyses show remarkable agreement between the model output and the observations, particularly in the 14 month, or Chandler, period band. The latter indicates that the enhanced pole tide found in the North Sea along the Denmark‐Netherlands coast is actually the coastal set-up response to wind stress forcing with a periodicity of around 14 months. We find no need to invoke a geophysical explanation involving resonance enhancement of the pole tide in the North Sea to explain the observations.