Operational Forecast System for the Salish Sea

Project Team

Project Lead/Scientific PI: Tarang Khangaonkar, Pacific Northwest National Laboratory (PNNL)

CO-PI: Hydrologist-TBD, Modeling and TMDL Washington State Department of Ecology

Transition PI: Jan Newton, NANOOS, University of Washington

Federal Collaborator (Operator Lead): Patrick Burke, NOAA/NOS

Federal Collaborator (Science Advisor): Edward Myers, NOAA/NOS

NOAA/NOS Technical Points of Contact: Lei Shi, Edward Myers, Audra Luscher, Carolyn Lindley, Machuan Peng

Collaborating Partners: Amy MacFadyen and Chris Barker (NOAA Office of Response and Restoration); Robert Daniels and John Jacobs (NOAA National Centers for Coastal Ocean Science), David Michalsen (USACE, Seattle District), Rohinee Paranjpye (NOAA Fisheries)

Project Overview and Results

The NOAA/NOS has identified the Salish Sea region of Pacific Northwest as a major data gap for NOS. Development of an OFS for the Salish Sea has become a higher priority as a result of heightened community-wide interest in real-time oceanographic information. In addition to NOAA mission goals and priorities related to navigation, the increased risk of oil spills due to an unanticipated spike in tanker traffic in the region, impacting NOAA and U.S. Coast Guard maritime emergency response, is of major concern. Also, annually recurring hypoxic events, exposure of shellfish farms to corrosive waters, seasonal harmful algal blooms, occurrences of shellfish poisoning, and exposure to over 100 wastewater plumes, are ecosystem management related challenges faced by the community that need and would benefit from information from this Salish Sea estuarine circulation model.

A diagnostic hydrodynamic and biogeochemical model (nutrients, phytoplankton, carbon, dissolved oxygen, pH) of the Salish Sea has already been developed and tested with the ability to simulate characteristic circulation and water quality features. The performance of the model to reproduce known circulation features within the Salish Sea, respond to land-based and oceanic nutrient loads to reproduce observed algal cycles and hypoxia and simulate sediment diagenesis processes and coupling to the water column has been documented. The Salish Sea Model (SSM) is used by state and local agencies responsible for the management of water quality and the ecosystems in Puget Sound and the greater Salish Sea for the analysis of circulation, water quality, and ecosystem response; and for nutrient pollution management, sea level rise, climate change, and ocean acidification.

The objective of the proposed scope of work is to incorporate improvements and conduct robust testing of the SSM for transition to NOS. The work scope and approach has been developed with the expectation that following completion of testing, SSM-OFS will be transitioned to CO-OPS for future maintenance and operation. Specifically, the following activities are proposed towards completion of the readiness levels and transitioning of SSM.

Model Descriptions

Salish Sea Model:

The Salish Sea is the nation’s 2nd largest marine estuarine system. It includes major port cities such as Vancouver, Seattle, Tacoma, Bellingham, Port Angeles and Victoria, but does not currently have an OFS. The focus of the University of Washington (UW) ROMS based model of the Salish Sea and associated studies has primarily been on the Pacific Northwest coastal shelf away from inner Salish Sea waters (Sutherland et al. 2011, Giddings et al., 2014; Davis et al., 2014; and Siedlecki et al., 2015). To resolve the inter-basin hydrodynamics, exchange, and biogeochemical response to nutrient pollution from over 100 wastewater outfalls and numerous non-point sources in the inner waters of the Salish Sea, PNNL, in collaboration with Ecology, developed an externally coupled hydrodynamic and biogeochemical model of the entire Salish Sea (Khangaonkar et al., 2011a; 2012). The model was constructed using the unstructured grid Finite Volume Community Ocean model (FVCOM; Chen et al., 2003) framework and integrated-compartment model biogeochemical water-quality kinetics (CE-QUAL-ICM; Cerco and Cole, 1994; 1995). Since then, the Salish Sea Model grid has been expanded to include coastal waters around Vancouver Island and the continental shelf from Canada’s Queen Charlotte Strait to Oregon’s Waldport (south of Yaquina Bay) and includes the Columbia River estuary (Khangaonkar et al. 2017). The model now also includes a carbonate chemistry module for ocean acidification and a sediment diagenesis module which allows direct coupled interaction between the water column and sediments through the processes of organic sediment settling, burial, and remineralization (Pelletier et al., 2017; Bianucci et al., 2018).

With the aid of above improvements and a detailed recalibration effort using data from 2014, the observed residual exchange flows and biogeochemical conditions of the Salish Sea including near-bed hypoxia have been reproduced successfully (Khangaonkar et al 2017b, 2018). Researchers from various state and federal agencies, engaged in efforts related to restoration of the Salish Sea and management of the coastal ecosystem utilize SSM extensively in a diagnostic mode as part of pollution management, coastal restoration and land-use, and other nearshore feasibility assessments. Based on its current use and status, and the COMT RL ontology (NOAA Administrative Order 215-105B), the SSM is at RL5. Availability of the extensive current survey data of Puget Sound completed by NOAA in 2017 facilitates this transition effort from RL5 to RL7 with robust testing using the new data.


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