A comparative study of 4D-VAR and a 4D Ensemble Kalman Filter: Perfect model simulations with Lorenz-96

Elana J. Fertig; John Harlim; Brian R. Hunt

doi:10.1111/j.1600-0870.2006.00205.x

A comparative study of 4D-VAR and a 4D Ensemble Kalman Filter: Perfect model simulations with Lorenz-96

Elana J. Fertig, John Harlim, Brian R. Hunt

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80 Scopus citations

Abstract

We formulate a four-dimensional Ensemble Kalman Filter (4D-LETKF) that minimizes a cost function similar to that in a 4D-VAR method. Using perfect model experiments with the Lorenz-96 model, we compare assimilation of simulated asynchronous observations with 4D-VAR and 4D-LETKF. We find that both schemes have comparable error when 4D-LETKF is performed sufficiently frequently and when 4D-VAR is performed over a sufficiently long analysis time window. We explore how the error depends on the time between analyses for 4D-LETKF and the analysis time window for 4D-VAR.

Original language	English (US)
Pages (from-to)	96-100
Number of pages	5
Journal	Tellus, Series A: Dynamic Meteorology and Oceanography
Volume	59
Issue number	1
DOIs	https://doi.org/10.1111/j.1600-0870.2006.00205.x
State	Published - Jan 2007
Externally published	Yes

ASJC Scopus subject areas

Oceanography
Atmospheric Science

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A comparative study of 4D-VAR and a 4D Ensemble Kalman Filter: Perfect model simulations with Lorenz-96

Abstract

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