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) | Download

GSI/EnKF System

The Community GSI V3.7 and EnKF V1.3 was released on 11/07/2018. This is the last official release for GSI and EnKF and there will be no further community releases beyond that.

Users who would like to access latest GSI and EnKF codes are encouraged to visit the authoritative GSI/EnKF repository on Github ( which is open to the public. A brief description on how to build the Github version GSI/EnKF is provided at

(NOTE: The GSI V3.7 and EnKF V1.3 does not build with any of the Intel v19 compilers. Please use v18 or earlier to compile the code.)  

Observation Resources

The GSI/EnKF requires specific data formats for observations to be assimilated:

  • Conventional observations (including satellite derived data, e.g., satellite wind):
    PrepBUFR format (NCEP featured BUFR format)
  • Satellite radiance data, GPS radio occultation data, Radar observations: 
    BUFR format

Descriptions about the data formats and links to some data resources are provided here.

External Libraries Needed To Build GSI/EnKF

The follow system/libraries are not in GSI/EnKF release package but needed for GSI/EnKF building:

    • A recent version of the CMake build system.
    • NetCDF: (note: NetCDF libraries need to be built with the same compiler as GSI/EnKF)
    • LAPACK and BLAS libraries may be needed. Check with your system administrator to see if local versions of these libraries already exist on your system.