A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter
This study considers a new hybrid three-dimensional variational (3D-Var) and ensemble Kalman filter (EnKF) data assimilation (DA) method in a non-perfect-model framework, named space-expanded ensemble localization Kalman filter (SELKF). In this method, the localization operation is directly applied...
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| Format: | Article |
| Language: | English |
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Wiley
2013-01-01
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| Series: | Advances in Meteorology |
| Online Access: | http://dx.doi.org/10.1155/2013/410812 |
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| author | Hongze Leng Junqiang Song Fengshun Lu Xiaoqun Cao |
| author_facet | Hongze Leng Junqiang Song Fengshun Lu Xiaoqun Cao |
| author_sort | Hongze Leng |
| collection | DOAJ |
| description | This study considers a new hybrid three-dimensional variational (3D-Var) and ensemble Kalman filter (EnKF) data assimilation (DA) method in a non-perfect-model framework, named space-expanded ensemble localization Kalman filter (SELKF). In this method, the localization operation is directly applied to the ensemble anomalies with a Schur Product, rather than to the full error covariance of the state in the EnKF. Meanwhile, the correction space of analysis increment is expanded to a space with larger dimension, and the rank of the forecast error covariance is significantly increased. This scheme can reduce the spurious correlations in the covariance and approximate the full-rank background error covariance well. Furthermore, a deterministic scheme is used to generate the analysis anomalies. The results show that the SELKF outperforms the perturbed EnKF given a relatively small ensemble size, especially when the length scale is relatively long or the observation error covariance is relatively small. |
| format | Article |
| id | doaj-art-cd77234e0da54b2e847ed012f51f521a |
| institution | Kabale University |
| issn | 1687-9309 1687-9317 |
| language | English |
| publishDate | 2013-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in Meteorology |
| spelling | doaj-art-cd77234e0da54b2e847ed012f51f521a2025-02-03T01:09:47ZengWileyAdvances in Meteorology1687-93091687-93172013-01-01201310.1155/2013/410812410812A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman FilterHongze Leng0Junqiang Song1Fengshun Lu2Xiaoqun Cao3College of Computer, National University of Defense Technology, Changsha 410073, ChinaCollege of Computer, National University of Defense Technology, Changsha 410073, ChinaChina Aerodynamics Research and Development Center, Mianyang, Sichuan 621000, ChinaCollege of Computer, National University of Defense Technology, Changsha 410073, ChinaThis study considers a new hybrid three-dimensional variational (3D-Var) and ensemble Kalman filter (EnKF) data assimilation (DA) method in a non-perfect-model framework, named space-expanded ensemble localization Kalman filter (SELKF). In this method, the localization operation is directly applied to the ensemble anomalies with a Schur Product, rather than to the full error covariance of the state in the EnKF. Meanwhile, the correction space of analysis increment is expanded to a space with larger dimension, and the rank of the forecast error covariance is significantly increased. This scheme can reduce the spurious correlations in the covariance and approximate the full-rank background error covariance well. Furthermore, a deterministic scheme is used to generate the analysis anomalies. The results show that the SELKF outperforms the perturbed EnKF given a relatively small ensemble size, especially when the length scale is relatively long or the observation error covariance is relatively small.http://dx.doi.org/10.1155/2013/410812 |
| spellingShingle | Hongze Leng Junqiang Song Fengshun Lu Xiaoqun Cao A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter Advances in Meteorology |
| title | A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter |
| title_full | A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter |
| title_fullStr | A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter |
| title_full_unstemmed | A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter |
| title_short | A New Data Assimilation Scheme: The Space-Expanded Ensemble Localization Kalman Filter |
| title_sort | new data assimilation scheme the space expanded ensemble localization kalman filter |
| url | http://dx.doi.org/10.1155/2013/410812 |
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