Project: Data Assimilative Modeling of Marine Ecosystems
Marine ecosystem models generally combine numerical representations of basic processes like biological production and consumption with ocean circulation to simulate complex dynamics, usually governing photosynthesizers, their grazers and the inorganic nutrients required for their growth. These models are necessary simplifications of nature, and accurate marine ecosystem simulation is subject to many unavoidable errors, including in processes, organisms and in conditions used to initialize simulations. This project focuses on methods that are used to rigorously constrain marine ecosystem models with observations of the natural system to better approximate the natural system. Specifically, we will focus on four-dimensional variational and ensemble Kalman filter approaches, two methods that are commonly used in physical oceanography and numerical weather prediction. We hope to produce accurate estimates of concentrations and fluxes that are critical to marine ecosystem dynamics in the California Current System and the ocean surrounding the Hawaiian Islands where observational programs can supply information to evaluate model output and benefit from model-produced estimates of fields that are difficult to measure directly.
Christopher Edwards is a professor in the Ocean Sciences Department at the University of California, Santa Cruz. He received his B.S. from Haverford College in 1988 and his Ph.D. from the Massachusetts Institute of Technology and Woods Hole Oceanographic Institution in 1997. He was a postdoctoral researcher at the University of California, Berkeley, and a research scientist at the University of Connecticut before becoming a faculty member at UC Santa Cruz in 2002.
Dr. Edwards’ research centers on the development and analysis of regional ocean models and methods of data assimilation used for studying ocean circulation, biogeochemistry and fisheries. His research presently focuses on physical and biological interactions within the California Current System, the collection of ocean currents off the U.S. west coast that include both time-mean and temporally variable motions at many scales. His group has studied how ocean circulation creates and organizes biogeographic provinces and habitats that associate with marine organisms and contribute to their connectivity. His group has pioneered application to marine ecosystems of a four-dimensional variational data assimilation method for state estimation that uses a logarithm transform to approximate the non-Gaussian statistics of biogeochemical variables in the ocean. Such methods enable accurate hindcasts of the physical and ecosystem state to understand how the ocean has changed in the past, and offer opportunities for modern ocean observing systems that focus on timely estimates and prediction of ocean properties.