CAREER: The relative importance of remote oceanic forcing on estuarine exchange flow across a broad parameter space - Numerical analysis integrated with visualization & education

University Of California-San Diego Scripps Inst Of Oceanography, La Jolla CA

Investigators

Abstract

Exchange between estuaries and the coastal ocean is a key dynamical driver affecting the flushing characteristics of an estuary (residence time) and impact critical biological and biogeochemical processes such as nutrient and phytoplankton concentrations, development of anoxic/hypoxic conditions and acidification across the estuary/ocean interface. Extensive research on the local forces (i.e., river flow, vertical mixing, tidal pumping due to bathymetry, local winds) driving estuarine exchange flows has helped advance knowledge of estuarine physics. However, the relative role of oceanic forcing (i.e., offshore plumes, coastal trapped waves, storm induced set-up, and wind driven upwelling / downwelling) is less understood, particularly across the different estuary types. This study aims at understanding the relative influence of remote oceanic forcing on estuarine exchange flow using numerical modeling applied across 10 different estuary types. Existing, validated, realistic numerical simulations are paired with semi-idealized and idealized numerical simulations for analysis. The scientific value of understanding the influence of remote forcing on estuarine exchange is broad given its impacts on important biological and biogeochemical processes, and more importantly, it will afford improved understanding of how estuaries may respond to future changes of oceanic and atmospheric conditions. In addition, as part of this study, research is integrated with education through the design of an interactive visualization tool for numerical simulations. This study employs a synthesis approach and uses simulations generated by numerous scientists. This brings together the estuarine research community to address scientific questions that could not be answered by individual estuary studies. The educational component of the work aims at building a community of scientist - educators that include scientists, education researchers and experts, secondary school teachers in science and computer science, undergraduate researchers, a postdoctoral researcher, and a graduate student. Valuable tools for both the research and education communities, including analysis codes, an interactive simulation visualization tool accompanied with lesson scaffolding curriculum content, and teaching resources will be developed and made publicly available. There is a knowledge gap on the relative importance of remote oceanic forcing on estuarine exchange flow and how this varies across different estuary types. This gap is addressed in this study where existing estuarine parameterizations are tested, and the results are mapped onto the appropriate parameter space. The synthesis of 10 different estuarine numerical models constitutes a novel way of approaching estuarine science - studying a variety of estuaries rather than one "favorite estuary." Specifically, the proposed work will (1) Calculate the estuarine exchange flow (as quantified by the Total Exchange Flow, TEF) across a wide estuarine parameter space (defined by the mixing parameter, M, and freshwater Froude number, Frf); (2) Quantify the role of remote oceanic forcing on TEF for different types and frequencies of remote forcing and on different estuary types and geometries; (3) Use model output to optimally design an observational array to measure these processes with TEF; (4) Integrate an interactive visualization tool of numerical simulation output with lesson scaffolding to produce educational tools and opportunities for integration between research and education This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.