Simultaneous measurements of tidal straining and advection at two parallel transects far downstream in the Rhine ROFI

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• 作者：Sabine Rijnsburger ; Carola M. van der Hout ; Onno van Tongeren…
• 刊名：Ocean Dynamics
• 出版年：2016
• 出版时间：May 2016
• 年：2016
• 卷：66
• 期：5
• 页码：719-736
• 全文大小：3,889 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Earth sciences
  Oceanography
  Geophysics and Geodesy
  Meteorology and Climatology
  Fluids
  Structural Foundations and Hydraulic Engineering
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：1616-7228
• 卷排序：66

文摘

This study identifies and unravels the processes that lead to stratification and destratification in the far field of a Region of Freshwater Influence (ROFI). We present measurements that are novel for two reasons: (1) measurements were carried out with two vessels that sailed simultaneously over two cross-shore transects; (2) the measurements were carried out in the far field of the Rhine ROFI, 80 km downstream from the river mouth. This unique four dimensional dataset allows the application of the 3D potential energy anomaly equation for one of the first times on field data. With this equation, the relative importance of the depth mean advection, straining and nonlinear processes over one tidal cycle is assessed. The data shows that the Rhine ROFI extends 80 km downstream and periodic stratification is observed. The analysis not only shows the important role of cross-shore tidal straining but also the significance of along-shore straining and depth mean advection. In addition, the nonlinear terms seem to be small. The presence of all the terms influences the timing of maximum stratification. The analysis also shows that the importance of each term varies in the cross-shore direction. One of the most interesting findings is that the data are not inline with several hypotheses on the functioning of straining and advection in ROFIs. This highlights the dynamic behaviour of the Rhine ROFI, which is valuable for understanding the distribution of fine sediments, contaminants and the protection of coasts.KeywordsRhine river plumeROFIPotential energy anomaly equationTidal straining and advectionIn situ measurements