Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1)
A fully coupled atmosphere–ocean–ice model has been used to produce global weather forecasts at Environment and Climate Change Canada (ECCC) since November 2017. Currently, the system relies on four uncoupled data assimilation (DA) components for initializing the fully coupled global atmosphere–ocea...
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ftdoajarticles:oai:doaj.org/article:aefb03005c2c400d9b8bb416627307e7 2023-05-15T18:18:30+02:00 Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) S. Skachko M. Buehner S. Laroche E. Lapalme G. Smith F. Roy D. Surcel-Colan J.-M. Bélanger L. Garand 2019-12-01T00:00:00Z https://doi.org/10.5194/gmd-12-5097-2019 https://doaj.org/article/aefb03005c2c400d9b8bb416627307e7 EN eng Copernicus Publications https://www.geosci-model-dev.net/12/5097/2019/gmd-12-5097-2019.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-12-5097-2019 1991-959X 1991-9603 https://doaj.org/article/aefb03005c2c400d9b8bb416627307e7 Geoscientific Model Development, Vol 12, Pp 5097-5112 (2019) Geology QE1-996.5 article 2019 ftdoajarticles https://doi.org/10.5194/gmd-12-5097-2019 2022-12-31T01:18:00Z A fully coupled atmosphere–ocean–ice model has been used to produce global weather forecasts at Environment and Climate Change Canada (ECCC) since November 2017. Currently, the system relies on four uncoupled data assimilation (DA) components for initializing the fully coupled global atmosphere–ocean–ice forecast model: atmosphere, ocean, sea ice and sea surface temperature (SST). The goal of the present study is to implement a weakly coupled data assimilation (WCDA) between the atmosphere and ocean components and evaluate its performance against uncoupled DA. The WCDA system uses coupled atmosphere–ocean–ice short-term forecasts as background states for the atmospheric and the ocean DA components that independently compute atmospheric and ocean analyses. This system leads to better agreement between the coupled atmosphere–ocean analyses and the coupled atmosphere–ocean–ice forecasts than between the uncoupled analyses and the coupled forecasts. The use of WCDA improves the atmospheric forecast score near the surface, but a slight increase in the atmospheric temperature bias is observed. A small positive impact from using the short-term SST forecast on the satellite radiance observation-minus-forecast statistics is noted. Ocean temperature and salinity forecasts are also improved near the surface. The next steps toward stronger DA coupling are highlighted. Article in Journal/Newspaper Sea ice Directory of Open Access Journals: DOAJ Articles Canada Geoscientific Model Development 12 12 5097 5112 |
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Open Polar |
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Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 |
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Geology QE1-996.5 S. Skachko M. Buehner S. Laroche E. Lapalme G. Smith F. Roy D. Surcel-Colan J.-M. Bélanger L. Garand Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) |
topic_facet |
Geology QE1-996.5 |
description |
A fully coupled atmosphere–ocean–ice model has been used to produce global weather forecasts at Environment and Climate Change Canada (ECCC) since November 2017. Currently, the system relies on four uncoupled data assimilation (DA) components for initializing the fully coupled global atmosphere–ocean–ice forecast model: atmosphere, ocean, sea ice and sea surface temperature (SST). The goal of the present study is to implement a weakly coupled data assimilation (WCDA) between the atmosphere and ocean components and evaluate its performance against uncoupled DA. The WCDA system uses coupled atmosphere–ocean–ice short-term forecasts as background states for the atmospheric and the ocean DA components that independently compute atmospheric and ocean analyses. This system leads to better agreement between the coupled atmosphere–ocean analyses and the coupled atmosphere–ocean–ice forecasts than between the uncoupled analyses and the coupled forecasts. The use of WCDA improves the atmospheric forecast score near the surface, but a slight increase in the atmospheric temperature bias is observed. A small positive impact from using the short-term SST forecast on the satellite radiance observation-minus-forecast statistics is noted. Ocean temperature and salinity forecasts are also improved near the surface. The next steps toward stronger DA coupling are highlighted. |
format |
Article in Journal/Newspaper |
author |
S. Skachko M. Buehner S. Laroche E. Lapalme G. Smith F. Roy D. Surcel-Colan J.-M. Bélanger L. Garand |
author_facet |
S. Skachko M. Buehner S. Laroche E. Lapalme G. Smith F. Roy D. Surcel-Colan J.-M. Bélanger L. Garand |
author_sort |
S. Skachko |
title |
Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) |
title_short |
Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) |
title_full |
Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) |
title_fullStr |
Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) |
title_full_unstemmed |
Weakly coupled atmosphere–ocean data assimilation in the Canadian global prediction system (v1) |
title_sort |
weakly coupled atmosphere–ocean data assimilation in the canadian global prediction system (v1) |
publisher |
Copernicus Publications |
publishDate |
2019 |
url |
https://doi.org/10.5194/gmd-12-5097-2019 https://doaj.org/article/aefb03005c2c400d9b8bb416627307e7 |
geographic |
Canada |
geographic_facet |
Canada |
genre |
Sea ice |
genre_facet |
Sea ice |
op_source |
Geoscientific Model Development, Vol 12, Pp 5097-5112 (2019) |
op_relation |
https://www.geosci-model-dev.net/12/5097/2019/gmd-12-5097-2019.pdf https://doaj.org/toc/1991-959X https://doaj.org/toc/1991-9603 doi:10.5194/gmd-12-5097-2019 1991-959X 1991-9603 https://doaj.org/article/aefb03005c2c400d9b8bb416627307e7 |
op_doi |
https://doi.org/10.5194/gmd-12-5097-2019 |
container_title |
Geoscientific Model Development |
container_volume |
12 |
container_issue |
12 |
container_start_page |
5097 |
op_container_end_page |
5112 |
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