Christopher Edwards, Ph.D.

CBIOMES Project: Northeast Pacific Ocean data assimilative microbial modeling and analysis

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. Data assimilation refers to formal methods that are used to constrain marine ecosystem models with observations of the natural system to better approximate the natural system. This procedure is similar to techniques used in weather forecasting. We have developed data assimilative methods that are particularly useful for complex marine ecosystems.

This project focuses on the application of these methods to constrain ecosystem models of the northeast Pacific. This region is interesting because it includes differing biomes representing different microbial community structure. This project will investigate whether data assimilative models can effectively influence these biomes to better encompass the observed microbial communities and constrain their boundaries to be more consistent with observed locations. This effort necessarily includes development of statistically derived remotely sensed and in situ data products that contain microbial community information. We will use a complex marine ecosystem model, the Darwin model, that is configured with sufficient diversity to represent the northeast Pacific. Studies will include both data assimilative investigations as well as non-data assimilative analyses that focus on how physical processes such as ocean circulation and internal waves influence marine ecosystems. We hope that the combination of numerical models, data and data assimilative methods yield new information on what controls marine microbial communities in the world ocean.

Bio:
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.

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