SODA aims at gathering and externalizing developments around data assimilation in SURFEX (OI or EKF in PNT or OFFLINE Surfex modes).

The last version of SODA was developed by Trygve Aspelien and put in the branch new_soda (based on trunk SVN SURFEX V7_3, revision 1290).

For the moment, VARASSIM from Alina Barbu is not merged with SODA. So, a question remains if VARASSIM has to be put in SURFEX V8, and if yes, if in or out of SODA.


  • second version of SODA (summer 2013)
  • New directory ASSIM for the assimilation related code.
  • Option to weight land/sea differently when calculating grid average T2M
  • Optional extrapolation of snow
  • OpenMP fixes
  • Optional extrapolation of variables in the prep step
  • Initialization of PZENITH in init_surf_atmn.F90 ( Applicable in the SODA case )
  • Optional bound of snow water equivalent in prep.
  • Fix for vegetation_update.F90

new_soda was merged with NEW_PREP in branch NEW_PREP_HIRLAM at the end of November 2013. Ulf Andrae used STRATO to test this new branch.

This branch was got by Yann Seity to enter AROME CY40t1 (with additional modifications from GMAP for SURFEX).

Trygve already provided a test case for SODA in the branch new_soda (MY_RUN/SODA). This test case remains to be included in the base of automatic tests (STRATO). This could be done in the same time as integrating the branch new_soda in V8 of SURFEX.

This contribution concerns a very specific feature of the SURFEX code (data assimilation) and will be included in the intermediate mergings for SURFEX V8. If the SURFEX version for CY40t1 is ended early enough, and tests performed, it could also be integrated from the beginning.