Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean
An ocean data assimilation system to assimilate Argo temperature ( T ) and salinity ( S ) profiles into the HYbrid Coordinate Ocean Model (HYCOM) was constructed, implemented and evaluated for the first time in the Atlantic Ocean (78° S to 50° N and 98° W to 20° E). The system is based on the ensemb...
Published in: | Ocean Science |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Copernicus Publications
2015
|
Subjects: | |
Online Access: | https://doi.org/10.5194/os-11-195-2015 https://doaj.org/article/6bec6e3561a7442b8174e63f563d55b6 |
id |
ftdoajarticles:oai:doaj.org/article:6bec6e3561a7442b8174e63f563d55b6 |
---|---|
record_format |
openpolar |
spelling |
ftdoajarticles:oai:doaj.org/article:6bec6e3561a7442b8174e63f563d55b6 2023-05-15T17:36:10+02:00 Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean D. Mignac C. A. S. Tanajura A. N. Santana L. N. Lima J. Xie 2015-02-01T00:00:00Z https://doi.org/10.5194/os-11-195-2015 https://doaj.org/article/6bec6e3561a7442b8174e63f563d55b6 EN eng Copernicus Publications http://www.ocean-sci.net/11/195/2015/os-11-195-2015.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-11-195-2015 https://doaj.org/article/6bec6e3561a7442b8174e63f563d55b6 Ocean Science, Vol 11, Iss 1, Pp 195-213 (2015) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2015 ftdoajarticles https://doi.org/10.5194/os-11-195-2015 2022-12-31T14:37:00Z An ocean data assimilation system to assimilate Argo temperature ( T ) and salinity ( S ) profiles into the HYbrid Coordinate Ocean Model (HYCOM) was constructed, implemented and evaluated for the first time in the Atlantic Ocean (78° S to 50° N and 98° W to 20° E). The system is based on the ensemble optimal interpolation (EnOI) algorithm proposed by Xie and Zhu (2010), especially made to deal with the hybrid nature of the HYCOM vertical coordinate system with multiple steps. The Argo T – S profiles were projected to the model vertical space to create pseudo-observed layer thicknesses (Δ p obs ), which correspond to the model target densities. The first step was to assimilate Δ p obs considering the sub-state vector composed by the model layer thickness (Δ p ) and the baroclinic velocity components. After that, T and S were assimilated separately. Finally, T was diagnosed below the mixed layer to preserve the density of the model isopycnal layers. Five experiments were performed from 1 January 2010 to 31 December 2012: a control run without assimilation, and four assimilation runs considering the different vertical localizations of T , S and Δ p . The assimilation experiments were able to significantly improve the thermohaline structure produced by the control run. They reduced the root mean square deviation (RMSD) of T and S calculated with respect to Argo independent data in 34 and 44%, respectively, in comparison to the control run. In some regions, such as the western North Atlantic, substantial corrections in the 20 °C isotherm depth and the upper ocean heat content towards climatological states were achieved. The runs with a vertical localization of Δ p showed positive impacts in the correction of the thermohaline structure and reduced the RMSD of T ( S ) from 0.993 °C (0.149 psu) to 0.905 °C (0.138 psu) for the whole domain with respect to the other assimilation runs. Article in Journal/Newspaper North Atlantic Directory of Open Access Journals: DOAJ Articles Ocean Science 11 1 195 213 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
spellingShingle |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 D. Mignac C. A. S. Tanajura A. N. Santana L. N. Lima J. Xie Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
An ocean data assimilation system to assimilate Argo temperature ( T ) and salinity ( S ) profiles into the HYbrid Coordinate Ocean Model (HYCOM) was constructed, implemented and evaluated for the first time in the Atlantic Ocean (78° S to 50° N and 98° W to 20° E). The system is based on the ensemble optimal interpolation (EnOI) algorithm proposed by Xie and Zhu (2010), especially made to deal with the hybrid nature of the HYCOM vertical coordinate system with multiple steps. The Argo T – S profiles were projected to the model vertical space to create pseudo-observed layer thicknesses (Δ p obs ), which correspond to the model target densities. The first step was to assimilate Δ p obs considering the sub-state vector composed by the model layer thickness (Δ p ) and the baroclinic velocity components. After that, T and S were assimilated separately. Finally, T was diagnosed below the mixed layer to preserve the density of the model isopycnal layers. Five experiments were performed from 1 January 2010 to 31 December 2012: a control run without assimilation, and four assimilation runs considering the different vertical localizations of T , S and Δ p . The assimilation experiments were able to significantly improve the thermohaline structure produced by the control run. They reduced the root mean square deviation (RMSD) of T and S calculated with respect to Argo independent data in 34 and 44%, respectively, in comparison to the control run. In some regions, such as the western North Atlantic, substantial corrections in the 20 °C isotherm depth and the upper ocean heat content towards climatological states were achieved. The runs with a vertical localization of Δ p showed positive impacts in the correction of the thermohaline structure and reduced the RMSD of T ( S ) from 0.993 °C (0.149 psu) to 0.905 °C (0.138 psu) for the whole domain with respect to the other assimilation runs. |
format |
Article in Journal/Newspaper |
author |
D. Mignac C. A. S. Tanajura A. N. Santana L. N. Lima J. Xie |
author_facet |
D. Mignac C. A. S. Tanajura A. N. Santana L. N. Lima J. Xie |
author_sort |
D. Mignac |
title |
Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean |
title_short |
Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean |
title_full |
Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean |
title_fullStr |
Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean |
title_full_unstemmed |
Argo data assimilation into HYCOM with an EnOI method in the Atlantic Ocean |
title_sort |
argo data assimilation into hycom with an enoi method in the atlantic ocean |
publisher |
Copernicus Publications |
publishDate |
2015 |
url |
https://doi.org/10.5194/os-11-195-2015 https://doaj.org/article/6bec6e3561a7442b8174e63f563d55b6 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Ocean Science, Vol 11, Iss 1, Pp 195-213 (2015) |
op_relation |
http://www.ocean-sci.net/11/195/2015/os-11-195-2015.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-11-195-2015 https://doaj.org/article/6bec6e3561a7442b8174e63f563d55b6 |
op_doi |
https://doi.org/10.5194/os-11-195-2015 |
container_title |
Ocean Science |
container_volume |
11 |
container_issue |
1 |
container_start_page |
195 |
op_container_end_page |
213 |
_version_ |
1766135564454592512 |