Removal of Content Advisory - April 2024

Advisory to Ensemble Kalman Filter (EnKF) users: As of the beginning of April 2024, all support assets for Ensemble Kalman Filter (EnKF) will be removed from the DTC website. Users should download all reference materials of interest prior to April 2024.

Ensemble Kalman Filter System (EnKF)

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Notice: as of January 2022 DTC has ceased all activities supporting the GSI/EnKF user community. For more details see the full announcement.


Welcome to the users page for the Community Ensemble Kalman Filter (EnKF) system. The community EnKF system is a Monte-Carlo algorithm for data assimilation that uses an ensemble of short-term forecasts to estimate the background-error covariance in the Kalman Filter. It is designed to be flexible, state-of-art, and run efficiently on various parallel computing platforms. The EnKF system is in the public domain and is freely available for community use.

The Developmental Testbed Center (DTC) maintained and supported a community version of the EnKF system (currently Version 1.3) as well as the community version of the Grid-point Statistical Interpolation (GSI) (now at Version 3.7) through 31 December 2021. The testing of this EnKF system at the DTC included both regional numerical weather prediction (NWP) applications coupled with the Weather Research and Forecasting (WRF) Model, as well as global NWP applications.

The EnKF uses the observation operators in the GSI system to transform model variables to observed variables in observation space. Therefore, the types of observations available for use in the EnKF match those for the GSI. EnKF Version 1.3 has been tested to work with the GSI Version 3.7. For a complete list of the new functions and changes included in the latest release version, please check EnKF User's Guide section 1.3.