Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter
peer reviewed In this paper, three incremental analysis update schemes (IAU 0, IAU 50 and IAU 100) are compared in the same assimilation experiments with a realistic eddy permitting primitive equation model of the North Atlantic Ocean using the Ensemble Kalman Filter. The difference between the thre...
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Online Access: | https://orbi.uliege.be/handle/2268/232437 https://orbi.uliege.be/bitstream/2268/232437/1/1-s2.0-S1463500317300653-main.pdf https://doi.org/10.1016/j.ocemod.2017.05.002 |
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ftorbi:oai:orbi.ulg.ac.be:2268/232437 2024-04-21T08:07:46+00:00 Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter Yan, Yajing Barth, Alexander Beckers, Jean-Marie Brankart, J. M. Brasseur, P. Candille, G. GHER 2017 https://orbi.uliege.be/handle/2268/232437 https://orbi.uliege.be/bitstream/2268/232437/1/1-s2.0-S1463500317300653-main.pdf https://doi.org/10.1016/j.ocemod.2017.05.002 en eng Elsevier Ltd info:eu-repo/grantAgreement/EC/FP7/283580 urn:issn:1463-5003 urn:issn:1463-5011 https://orbi.uliege.be/handle/2268/232437 info:hdl:2268/232437 https://orbi.uliege.be/bitstream/2268/232437/1/1-s2.0-S1463500317300653-main.pdf doi:10.1016/j.ocemod.2017.05.002 scopus-id:2-s2.0-85019910116 open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess Ocean Modelling, 115, 27-41 (2017) Comparison Ensemble Kalman Filter Incremental analysis update Probabilistic metrics Bandpass filters Integration Continuous ranked probability scores Ensemble forecast systems Equilibrium modeling Incremental analysis North Atlantic Ocean Kalman filters Kalman filter Atlantic Ocean Atlantic Ocean (North) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique journal article http://purl.org/coar/resource_type/c_6501 info:eu-repo/semantics/article peer reviewed 2017 ftorbi https://doi.org/10.1016/j.ocemod.2017.05.002 2024-03-27T14:53:59Z peer reviewed In this paper, three incremental analysis update schemes (IAU 0, IAU 50 and IAU 100) are compared in the same assimilation experiments with a realistic eddy permitting primitive equation model of the North Atlantic Ocean using the Ensemble Kalman Filter. The difference between the three IAU schemes lies on the position of the increment update window. The relevance of each IAU scheme is evaluated through analyses on both thermohaline and dynamical variables. The validation of the assimilation results is performed according to both deterministic and probabilistic metrics against different sources of observations. For deterministic validation, the ensemble mean and the ensemble spread are compared to the observations. For probabilistic validation, the continuous ranked probability score (CRPS) is used to evaluate the ensemble forecast system according to reliability and resolution. The reliability is further decomposed into bias and dispersion by the reduced centred random variable (RCRV) score. The obtained results show that 1) the IAU 50 scheme has the same performance as the IAU 100 scheme 2) the IAU 50/100 schemes outperform the IAU 0 scheme in error covariance propagation for thermohaline variables in relatively stable region, while the IAU 0 scheme outperforms the IAU 50/100 schemes in dynamical variables estimation in dynamically active region 3) in case with sufficient number of observations and good error specification, the impact of IAU schemes is negligible. The differences between the IAU 0 scheme and the IAU 50/100 schemes are mainly due to different model integration time and different instability (density inversion, large vertical velocity, etc.) induced by the increment update. The longer model integration time with the IAU 50/100 schemes, especially the free model integration, on one hand, allows for better re-establishment of the equilibrium model state, on the other hand, smooths the strong gradients in dynamically active region. © 2017 Elsevier Ltd Article in Journal/Newspaper North Atlantic University of Liège: ORBi (Open Repository and Bibliography) Ocean Modelling 115 27 41 |
institution |
Open Polar |
collection |
University of Liège: ORBi (Open Repository and Bibliography) |
op_collection_id |
ftorbi |
language |
English |
topic |
Comparison Ensemble Kalman Filter Incremental analysis update Probabilistic metrics Bandpass filters Integration Continuous ranked probability scores Ensemble forecast systems Equilibrium modeling Incremental analysis North Atlantic Ocean Kalman filters Kalman filter Atlantic Ocean Atlantic Ocean (North) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
spellingShingle |
Comparison Ensemble Kalman Filter Incremental analysis update Probabilistic metrics Bandpass filters Integration Continuous ranked probability scores Ensemble forecast systems Equilibrium modeling Incremental analysis North Atlantic Ocean Kalman filters Kalman filter Atlantic Ocean Atlantic Ocean (North) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique Yan, Yajing Barth, Alexander Beckers, Jean-Marie Brankart, J. M. Brasseur, P. Candille, G. Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter |
topic_facet |
Comparison Ensemble Kalman Filter Incremental analysis update Probabilistic metrics Bandpass filters Integration Continuous ranked probability scores Ensemble forecast systems Equilibrium modeling Incremental analysis North Atlantic Ocean Kalman filters Kalman filter Atlantic Ocean Atlantic Ocean (North) Physical chemical mathematical & earth Sciences Earth sciences & physical geography Physique chimie mathématiques & sciences de la terre Sciences de la terre & géographie physique |
description |
peer reviewed In this paper, three incremental analysis update schemes (IAU 0, IAU 50 and IAU 100) are compared in the same assimilation experiments with a realistic eddy permitting primitive equation model of the North Atlantic Ocean using the Ensemble Kalman Filter. The difference between the three IAU schemes lies on the position of the increment update window. The relevance of each IAU scheme is evaluated through analyses on both thermohaline and dynamical variables. The validation of the assimilation results is performed according to both deterministic and probabilistic metrics against different sources of observations. For deterministic validation, the ensemble mean and the ensemble spread are compared to the observations. For probabilistic validation, the continuous ranked probability score (CRPS) is used to evaluate the ensemble forecast system according to reliability and resolution. The reliability is further decomposed into bias and dispersion by the reduced centred random variable (RCRV) score. The obtained results show that 1) the IAU 50 scheme has the same performance as the IAU 100 scheme 2) the IAU 50/100 schemes outperform the IAU 0 scheme in error covariance propagation for thermohaline variables in relatively stable region, while the IAU 0 scheme outperforms the IAU 50/100 schemes in dynamical variables estimation in dynamically active region 3) in case with sufficient number of observations and good error specification, the impact of IAU schemes is negligible. The differences between the IAU 0 scheme and the IAU 50/100 schemes are mainly due to different model integration time and different instability (density inversion, large vertical velocity, etc.) induced by the increment update. The longer model integration time with the IAU 50/100 schemes, especially the free model integration, on one hand, allows for better re-establishment of the equilibrium model state, on the other hand, smooths the strong gradients in dynamically active region. © 2017 Elsevier Ltd |
author2 |
GHER |
format |
Article in Journal/Newspaper |
author |
Yan, Yajing Barth, Alexander Beckers, Jean-Marie Brankart, J. M. Brasseur, P. Candille, G. |
author_facet |
Yan, Yajing Barth, Alexander Beckers, Jean-Marie Brankart, J. M. Brasseur, P. Candille, G. |
author_sort |
Yan, Yajing |
title |
Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter |
title_short |
Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter |
title_full |
Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter |
title_fullStr |
Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter |
title_full_unstemmed |
Comparison of different incremental analysis update schemes in a realistic assimilation system with Ensemble Kalman Filter |
title_sort |
comparison of different incremental analysis update schemes in a realistic assimilation system with ensemble kalman filter |
publisher |
Elsevier Ltd |
publishDate |
2017 |
url |
https://orbi.uliege.be/handle/2268/232437 https://orbi.uliege.be/bitstream/2268/232437/1/1-s2.0-S1463500317300653-main.pdf https://doi.org/10.1016/j.ocemod.2017.05.002 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_source |
Ocean Modelling, 115, 27-41 (2017) |
op_relation |
info:eu-repo/grantAgreement/EC/FP7/283580 urn:issn:1463-5003 urn:issn:1463-5011 https://orbi.uliege.be/handle/2268/232437 info:hdl:2268/232437 https://orbi.uliege.be/bitstream/2268/232437/1/1-s2.0-S1463500317300653-main.pdf doi:10.1016/j.ocemod.2017.05.002 scopus-id:2-s2.0-85019910116 |
op_rights |
open access http://purl.org/coar/access_right/c_abf2 info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.ocemod.2017.05.002 |
container_title |
Ocean Modelling |
container_volume |
115 |
container_start_page |
27 |
op_container_end_page |
41 |
_version_ |
1796947812335747072 |