HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development

<p>Decadal-scale oceanographic, environmental, and ecological changes have been reported in the Salish Sea, an ecologically productive inland sea in the northeast Pacific that supports the economies and cultures of millions of people. However, there are substantial data gaps related to physica...

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Main Authors: G. Oldford, T. Jarníková, V. Christensen, M. Dunphy
Format: Article
Language:English
Published: Copernicus Publications 2025-01-01
Series:Geoscientific Model Development
Online Access:https://gmd.copernicus.org/articles/18/211/2025/gmd-18-211-2025.pdf
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author G. Oldford
G. Oldford
T. Jarníková
V. Christensen
M. Dunphy
author_facet G. Oldford
G. Oldford
T. Jarníková
V. Christensen
M. Dunphy
author_sort G. Oldford
collection DOAJ
description <p>Decadal-scale oceanographic, environmental, and ecological changes have been reported in the Salish Sea, an ecologically productive inland sea in the northeast Pacific that supports the economies and cultures of millions of people. However, there are substantial data gaps related to physical water properties that make it difficult to evaluate trends and the pathways of effects between physical ocean water properties and the productivity of marine ecosystems. With the aim of addressing these gaps, we present the Hindcast of the Salish Sea (HOTSSea) v1, a 3D physical oceanographic model developed using the Nucleus for European Modelling of the Ocean (NEMO) ocean engine, with temporal coverage from 1980–2018. We used an experimental approach to incrementally assess sensitivity to atmospheric and ocean reanalysis products used for boundary forcings and to the horizontal discretisation of the model grid (<span class="inline-formula">∼</span> 1.5 km). Biases inherited from forcings were quantified, and a simple temperature bias correction factor applied at one ocean boundary was found to substantially improve model skill. Evaluation of salinity and temperature indicates performance is best in the Strait of Georgia. Relatively large biases occur in near-surface waters, especially in subdomains with topography narrower than the model grid's horizontal resolution. However, we demonstrated that the model simulates temperature anomalies and a secular warming trend over the entire water column in general agreement with observations. HOTSSea v1 provided a first look at spatially and temporally heterogenous ocean temperature trends throughout the northern and central part of the domain where observations are sparse. Overall, despite the biases inherited from forcings and a relatively coarse horizontal discretisation, HOTSSea v1 performs well at representing temperature and salinity at the spatial–temporal scales needed to support research related to decadal-scale climate effects on marine ecosystems, fish, and fisheries. We conclude by underscoring the need to further extend the hindcast to capture a regime shift that occurred in the 1970s.</p>
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language English
publishDate 2025-01-01
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series Geoscientific Model Development
spelling doaj-art-18d350f0fe284082a2cb81d1c7bc662c2025-01-20T07:17:09ZengCopernicus PublicationsGeoscientific Model Development1991-959X1991-96032025-01-011821123710.5194/gmd-18-211-2025HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model developmentG. Oldford0G. Oldford1T. Jarníková2V. Christensen3M. Dunphy4Institute for Oceans and Fisheries, University of British Columbia, Vancouver, V6T 1Z4, CanadaEcosystem Sciences Division, Fisheries and Oceans Canada, Nanaimo, V9T 6N7, CanadaTyndall Centre for Climate Change Research, School of Environmental Sciences, University of East Anglia, Norwich, UKInstitute for Oceans and Fisheries, University of British Columbia, Vancouver, V6T 1Z4, CanadaOcean Sciences Division, Institute of Ocean Sciences, Fisheries and Oceans Canada, Sidney, V8L 5T5, Canada<p>Decadal-scale oceanographic, environmental, and ecological changes have been reported in the Salish Sea, an ecologically productive inland sea in the northeast Pacific that supports the economies and cultures of millions of people. However, there are substantial data gaps related to physical water properties that make it difficult to evaluate trends and the pathways of effects between physical ocean water properties and the productivity of marine ecosystems. With the aim of addressing these gaps, we present the Hindcast of the Salish Sea (HOTSSea) v1, a 3D physical oceanographic model developed using the Nucleus for European Modelling of the Ocean (NEMO) ocean engine, with temporal coverage from 1980–2018. We used an experimental approach to incrementally assess sensitivity to atmospheric and ocean reanalysis products used for boundary forcings and to the horizontal discretisation of the model grid (<span class="inline-formula">∼</span> 1.5 km). Biases inherited from forcings were quantified, and a simple temperature bias correction factor applied at one ocean boundary was found to substantially improve model skill. Evaluation of salinity and temperature indicates performance is best in the Strait of Georgia. Relatively large biases occur in near-surface waters, especially in subdomains with topography narrower than the model grid's horizontal resolution. However, we demonstrated that the model simulates temperature anomalies and a secular warming trend over the entire water column in general agreement with observations. HOTSSea v1 provided a first look at spatially and temporally heterogenous ocean temperature trends throughout the northern and central part of the domain where observations are sparse. Overall, despite the biases inherited from forcings and a relatively coarse horizontal discretisation, HOTSSea v1 performs well at representing temperature and salinity at the spatial–temporal scales needed to support research related to decadal-scale climate effects on marine ecosystems, fish, and fisheries. We conclude by underscoring the need to further extend the hindcast to capture a regime shift that occurred in the 1970s.</p>https://gmd.copernicus.org/articles/18/211/2025/gmd-18-211-2025.pdf
spellingShingle G. Oldford
G. Oldford
T. Jarníková
V. Christensen
M. Dunphy
HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development
Geoscientific Model Development
title HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development
title_full HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development
title_fullStr HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development
title_full_unstemmed HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development
title_short HOTSSea v1: a NEMO-based physical Hindcast of the Salish Sea (1980–2018) supporting ecosystem model development
title_sort hotssea v1 a nemo based physical hindcast of the salish sea 1980 2018 supporting ecosystem model development
url https://gmd.copernicus.org/articles/18/211/2025/gmd-18-211-2025.pdf
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