[en] The Ensemble Kalman filter (EnKF) has been applied to a 1-D complex ecosystem model coupled with a hydrodynamic model of the Ligurian Sea. In order to improve the performance of the EnKF, an ensemble subsampling strategy has been used to better represent the covariance matrices and a pre-analysis step for correcting the non-normality of the members distribution has been implemented. Twin experiments have been realized to assess the performance of the developed tool and a real data assimilation experiment has been conducted to hindcast the ecosystem at the Dyfamed site during the year 2000. Finally the performance of the EnKF has been compared with a Singular Evolutive Extended Kalman (SEEK) filter with a fixed basis. We conclude that, on one hand, there is a benefit in using the subsampling strategy and the lognormal transformation with the EnKF, and on the other hand, this filter presents better performance than the fixed basis version of the SEEK filter. However, it also incurs a large computational cost.
Research center :
MARE - Centre Interfacultaire de Recherches en Océanologie - ULiège
Disciplines :
Physical, chemical, mathematical & earth Sciences: Multidisciplinary, general & others
Author, co-author :
Lenartz, Fabian ; Université de Liège - ULiège > Département d'astrophys., géophysique et océanographie (AGO) > Département d'astrophys., géophysique et océanographie (AGO)
Raick, Caroline ; Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Océanologie
Soetaert, Karline
Grégoire, Marilaure ; Université de Liège - ULiège > Département des sciences et gestion de l'environnement > Océanologie
Language :
English
Title :
Application of an ensemble Kalman Filter to a 1D coupled physical-biological model of the Ligurian sea
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