Sensitivity of Circulation and Biogeochemical Response in Puget Sound to Sea Level Rise and Future Climate Loads
Presentation Abstract
Assessments using future climate conditions based on the Intergovernmental Panel on Climate Change emissions scenario (A1B) have shown that hydrology of major rivers and freshwater runoff from multiple watersheds to Puget Sound, Washington, will be affected. In general, higher winter floods and lower summer flows coupled with future sea level rise have the potential to impact circulation and estuarine exchange. The effects on water properties such as temperature profiles, salinity gradients, and biogeochemical interactions are of interest due to concern over loss of coastal brackish habitats and potential impairment of water quality. In this paper we present a sensitivity analysis using the Puget Sound Georgia Basin hydrodynamic and biogeochemical model based on unstructured grid Finite Volume Coastal Ocean Model (FVCOM) framework and the CE QUAL-ICM model water quality kinetics. Effects of modified hydrology, sea level rise, and nutrient loads corresponding to years 2020, 2040, and 2070 are compared with baseline conditions from 2006. We examine potential large scale changes to the seasonal net transport through the various sub-basins within Puget Sound and also provide a relative comparison of key water quality parameters such as dissolved oxygen, nutrients, and algae. Simulation results indicate that the circulation and biogeochemical cycles within the Puget Sound Georgia Basin system are dominated by the strong estuarine exchange inflow from the Pacific Ocean. This exchange flow into Puget Sound is predicted to increase in response to the future forcing conditions resulting in higher influx of nutrient rich saline water from the Pacific Ocean. Although the magnitude of the predicted response in the main basin and deeper reaches of Puget Sound is relatively small, we note that higher nutrient loads in the intertidal zones and the shallow stratified reaches could lead to conditions suitable for algae blooms and exacerbate the low DO levels in the future.
Session Title
Session S-02A: Future Salish Sea Water Quality
Conference Track
Marine Water Quality
Conference Name
Salish Sea Ecosystem Conference (2014 : Seattle, Wash.)
Document Type
Event
Start Date
30-4-2014 1:30 PM
End Date
30-4-2014 3:00 PM
Location
Room 615-616-617
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Tidal currents--Salish Sea (B.C. and Wash.); Ocean circulation--Salish Sea (B.C. and Wash.); Climatic changes--Salish Sea (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.
Type
Text
Language
English
Format
application/pdf
Sensitivity of Circulation and Biogeochemical Response in Puget Sound to Sea Level Rise and Future Climate Loads
Room 615-616-617
Assessments using future climate conditions based on the Intergovernmental Panel on Climate Change emissions scenario (A1B) have shown that hydrology of major rivers and freshwater runoff from multiple watersheds to Puget Sound, Washington, will be affected. In general, higher winter floods and lower summer flows coupled with future sea level rise have the potential to impact circulation and estuarine exchange. The effects on water properties such as temperature profiles, salinity gradients, and biogeochemical interactions are of interest due to concern over loss of coastal brackish habitats and potential impairment of water quality. In this paper we present a sensitivity analysis using the Puget Sound Georgia Basin hydrodynamic and biogeochemical model based on unstructured grid Finite Volume Coastal Ocean Model (FVCOM) framework and the CE QUAL-ICM model water quality kinetics. Effects of modified hydrology, sea level rise, and nutrient loads corresponding to years 2020, 2040, and 2070 are compared with baseline conditions from 2006. We examine potential large scale changes to the seasonal net transport through the various sub-basins within Puget Sound and also provide a relative comparison of key water quality parameters such as dissolved oxygen, nutrients, and algae. Simulation results indicate that the circulation and biogeochemical cycles within the Puget Sound Georgia Basin system are dominated by the strong estuarine exchange inflow from the Pacific Ocean. This exchange flow into Puget Sound is predicted to increase in response to the future forcing conditions resulting in higher influx of nutrient rich saline water from the Pacific Ocean. Although the magnitude of the predicted response in the main basin and deeper reaches of Puget Sound is relatively small, we note that higher nutrient loads in the intertidal zones and the shallow stratified reaches could lead to conditions suitable for algae blooms and exacerbate the low DO levels in the future.
