Cristin-resultat-ID: 1236448
Sist endret: 25. oktober 2016 14:39
NVI-rapporteringsår: 2015
Resultat
Vitenskapelig artikkel
2015

Mitigating Observation Perturbation Sampling Errors in the Stochastic EnKF

Bidragsytere:
  • Ibrahim Hoteit
  • Dinh-Tuan Pham
  • Mohamad El Gharamti og
  • Xiaodong Luo

Tidsskrift

Monthly Weather Review
ISSN 0027-0644
e-ISSN 1520-0493
NVI-nivå 1

Om resultatet

Vitenskapelig artikkel
Publiseringsår: 2015
Volum: 143
Hefte: 7
Sider: 2918 - 2936

Importkilder

Scopus-ID: 2-s2.0-84943424519

Beskrivelse Beskrivelse

Tittel

Mitigating Observation Perturbation Sampling Errors in the Stochastic EnKF

Sammendrag

The stochastic ensemble Kalman filter (EnKF) updates its ensemble members with observations perturbed with noise sampled from the distribution of the observational errors. This was shown to introduce noise into the system, and may become pronounced when the ensemble size is smaller than the rank of the observational error covariance, which is often the case in real oceanic and atmospheric data assimilation applications. This work introduces an efficient serial scheme to mitigate the impact of observations perturbations sampling in the analysis step of the EnKF, which should provide more accurate ensemble estimates of the analysis error covariance matrices. The new scheme is simple to implement within the serial EnKF algorithm, requiring only the approximation of the EnKF sample forecast error covariance matrix by a matrix with one rank less. The new EnKF scheme is implemented and tested with the Lorenz-96 model. Results from numerical experiments are conducted to compare its performance with the EnKF and two standard deterministic EnKFs. We show that the new scheme enhances the behavior of the EnKF and may lead to better performance than the deterministic EnKFs even when implemented with relatively small ensembles.

Bidragsytere

Ibrahim Hoteit

  • Tilknyttet:
    Forfatter
    ved King Abdullah University of Science and Technology

Dinh-Tuan Pham

  • Tilknyttet:
    Forfatter
    ved Centre national de la recherche scientifique

Mohamed El Gharamti

Bidragsyterens navn vises på dette resultatet som Mohamad El Gharamti
  • Tilknyttet:
    Forfatter
    ved Nansen Senter for Miljø og Fjernmåling
  • Tilknyttet:
    Forfatter
    ved King Abdullah University of Science and Technology

Xiaodong Luo

  • Tilknyttet:
    Forfatter
    ved NORCE Energi ved NORCE Norwegian Research Centre AS
1 - 4 av 4