San Francisco Bay-Delta Hydrodynamics and Transport

Related Research Areas
Carbon Cycle & Ecosystems, Earth Surface & Interior, Water & Energy Cycles
Project Description
Our project endeavors to create, calibrate and support a 3D model of the San Francisco Bay-Delta. The model will be used to answer policy questions by the Department of Water Resources, and is the estuary component of SESAME, an energy-based full life cycle model of salmon migration being undertaken by NASA, DWR and the National Marine Fisheries Service. NASA is providing high resolution atmospheric inputs (from climate re-analysis) to the model as well as computational support. The long-term goal of our project is to develop an open-source, cross-scale multidimensional model suitable to answer flow and water quality questions involving large extents on the Bay-Delta system over periods of several years. Target applications include: • Habitat creation and conveyance options under BDCP alternatives • Salinity intrusion changes under drought or sea level rise • Velocity changes in nearby channels following the installation of barriers • Fate of mercury produced in the Liberty Island complex in the North Delta • Temperature, flow and food production in the estuary as part of a 3-model full life cycle bioenergetic model of salmon (as participants in the NOAA SESAME project). These applications vary a great deal in scope. The hydrodynamics code we are using is SELFE, a semi-implicit Eulerian-Lagrangian code that has been applied in similar estuaries around the world. SELFE has an accurate, robust solver that scales well on the high-performance architectures at NASA. In our collaboration with NOAA and NASA in the SESAME project, the flexibility and openness of SELFE allowed swift incorporation of CoSINE, an alternate nutrient model to the standard EcoSIM 2.0 in SELFE emphasizing the most important constituents for salmon in the system. Some of the challenge of the project thus far comes from the extreme variation of scale in the estuary. The intricate channels of the Delta need to be well represented without over-resolution. Our immediate goal has been to establish a foundation -- to develop a sense of global accuracy, requiring that we resolve (or craftily underresolve) the main mechanisms of hydrodynamics and transport up the estuary and in Delta channels: gravitational circulation and exchange flow; periodic stratification; tidal trapping; flood-ebb asymmetry of flow paths; shear dispersion; primary flow streamlines and perhaps some secondary circulation in large channels. Although we expect our calibration to continue to improve, most of further work will be conducted in project-dependent directions. Due to its flexible mesh, the model is easily re-usable in a near field - far field arrangement whereby the base model provides a pre-calibrated background grid for an extension or focal region of study. The Delta Modeling Section at DWR and Virginia Institute of Marine Sciences recently concluded a collaborative initial calibration of the 3D SELFE hydrodynamic model for the Bay-Delta. A technically comprehensive calibration document is in preparation.
Project Administrator(s):
Eli Ateljevich


Eli Ateljevich