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G.J. de Boer

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3 records found

Abstract (2018) - Julie Pietrzak, Gerben de Boer, Alexander R. Horner-Devine, Susan Allen, Alex Souza
The Rhine ROFI is a shallow, tidal, river plume dominated by tidal straining that has a major effect on the transport and dispersion of freshwater in the southern North Sea. We use a numerical model to explore the response of the Rhine ROFI to upwelling and downwelling winds. Using a potential energy anomaly (') analysis we find that as tidal straining moves the plume onshore during ebb tides it decreases the stratification and as it moves the plume offshore during flood tides it increases the stratification. We show that the overall effect of downwelling winds is to narrow the ROFI and decrease stratification, while upwelling winds spread the ROFI offshore and increase stratification. However, the plume does not continue to advect and disperse offshore during upwelling winds as in classic wind driven river plumes, but instead tidal straining limits the offshore displacement. This is due to a net onshore flux of freshwater caused by alongshore tidal straining the plume, as a result of which the plume is more fresh during the onshore phase of the tide, than during the offshore tidal phase. In contrast we show that the onshore displacement of the plume due to downwelling winds is enhanced by tidal straining. Using the volume integral of ' we show that upwelling favourable winds suppress the downwelling tidal straining phase of the tide during which convective mixing occurs. In contrast it enhances the upwelling phase during which straining increases stratification. The opposite happens for downwelling winds. Field data from the STRAINS experiments show the on and offshore advection of the plume during upwelling and downwelling favourable winds and are in reasonable agreement with the idealised model. ...
Conference paper (2014) - Gerben de Boer, Fedor Baart, B Jagers, B.P.J. Becker
Assessment of environmental status and integral safety requires combination of information from many sources, coming from either databases or increasingly via live model (scenario) simulations. Many of these models require input from one another, sometimes unidirectional, but more and more two-directional as well. Many protocols and frameworks are available for model coupling, often based on open standards and implementations. Previous overviews of coupling protocols have focused on data exchange volume, data complexity, invasiveness into existing models and support for specific programming languages. We extend the overview using recent developments in web-based protocols and focus on the suitability for internet-based data exchange. We also extend the focus of previous reviews by also taking the coupling with aggregated information products for end-users into account. We propose a hierarchical ordering of all standards for specific types of end-users. ...