Presentation Abstract

There is much interest in the Pacific Northwest community and water quality management agencies to better understand and predict long term changes in the Salish Sea water quality given periodic occurrences of hypoxia and evidence of coastal acidification. However, the projected interaction of riverine and estuarine systems under potential future climate-change scenarios is not well characterized in the Salish Sea area. In this study, the Salish Sea Model of circulation and water quality developed using FVCOM-ICM model was applied to provide insights on how estuarine/nearshore environments may be impacted in the future. It serves as a proof-of-concept assessment of the methods to functionally link downscaled outputs of CESM models for the Pacific Northwest (meteorology and biogeochemistry) to a marine circulation and water-quality model. We present simulated 100-year changes under the RCP8.5 scenario, including projected future increases in air temperature (≈+3.5˚), Pacific Ocean temperature (≈ +2.4°C), and river flow temperatures (≈+3.2°C), in combination with a projected sea level rise of +1.5m and future ocean chemistry changes. Our results show that strong vertical circulation cells in Salish Sea provide mitigation through mixing and continue to serve as a physical buffer, keeping water temperature cooler than over the continental shelf. Despite the mitigation effects, under RCP 8.5 scenario Salish Sea is expected to undergo several significant changes, including: temperature increases (+1.8°C), hypoxia zone expansion, and potential algal species shift (dinoflagellates: +196%; diatom: -14%). Snohomish Estuary, as an intertidal site example, is projected to experience 3 ˚C annual mean surface temperature increase and substantial seawater intrusion.

Session Title

Understanding the Salish Sea Model and its Application for Puget Sound Recovery

Conference Track

SSE15: Data and Information Management

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE15-114

Start Date

4-4-2018 2:15 PM

End Date

4-4-2018 2:30 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

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

Share

COinS
 
Apr 4th, 2:15 PM Apr 4th, 2:30 PM

Response of Salish Sea circulation and water quality to climate change and sea level rise

There is much interest in the Pacific Northwest community and water quality management agencies to better understand and predict long term changes in the Salish Sea water quality given periodic occurrences of hypoxia and evidence of coastal acidification. However, the projected interaction of riverine and estuarine systems under potential future climate-change scenarios is not well characterized in the Salish Sea area. In this study, the Salish Sea Model of circulation and water quality developed using FVCOM-ICM model was applied to provide insights on how estuarine/nearshore environments may be impacted in the future. It serves as a proof-of-concept assessment of the methods to functionally link downscaled outputs of CESM models for the Pacific Northwest (meteorology and biogeochemistry) to a marine circulation and water-quality model. We present simulated 100-year changes under the RCP8.5 scenario, including projected future increases in air temperature (≈+3.5˚), Pacific Ocean temperature (≈ +2.4°C), and river flow temperatures (≈+3.2°C), in combination with a projected sea level rise of +1.5m and future ocean chemistry changes. Our results show that strong vertical circulation cells in Salish Sea provide mitigation through mixing and continue to serve as a physical buffer, keeping water temperature cooler than over the continental shelf. Despite the mitigation effects, under RCP 8.5 scenario Salish Sea is expected to undergo several significant changes, including: temperature increases (+1.8°C), hypoxia zone expansion, and potential algal species shift (dinoflagellates: +196%; diatom: -14%). Snohomish Estuary, as an intertidal site example, is projected to experience 3 ˚C annual mean surface temperature increase and substantial seawater intrusion.