Controlling noise in ensemble data assimilation schemes

Malaquias Peña, Zoltan Toth, Mozheng Wei

Research output: Contribution to journalArticle

4 Citations (Scopus)


A variety of ad hoc procedures have been developed to prevent filter divergence in ensemble-based data assimilation schemes. These procedures are necessary to reduce the impacts of sampling errors in the background error covariance matrix derived from a limited-size ensemble. The procedures amount to the introduction of additional noise into the assimilation process, possibly reducing the accuracy of the resulting analyses. The effects of this noise on analysis and forecast performance are investigated in a perfect model scenario. Alternative schemes aimed at controlling the unintended injection of noise are proposed and compared. Improved analysis and forecast accuracy is observed in schemes with minimal alteration to the evolving ensemble-based covariance structure.

Original languageEnglish
Pages (from-to)1502-1512
Number of pages11
JournalMonthly Weather Review
Issue number5
Publication statusPublished - May 1 2010



  • Data assimilation
  • Ensembles
  • Kalman filters
  • Model evaluation/performance
  • Numerical analysis/modeling

ASJC Scopus subject areas

  • Atmospheric Science

Cite this