Original Research Papers
A comparative study of 4D-VAR and a 4D Ensemble Kalman Filter: perfect model simulations with Lorenz-96
Authors:
- Elana J. FertigEmail Elana J. Fertig
- John Harlim
- Brian R. Hunt
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.
- Year: 2007
- Volume: 59 Issue: 1
- Page/Article: 96–100
- DOI: 10.1111/j.1600-0870.2006.00205.x
- Submitted on 7 Jun 2006
- Accepted on 22 Aug 2006
- Published on 1 Jan 2007
- Peer Reviewed