= Optimization of the SOil freezing parameterization =


* Soil freezing follows from the initial work of Isabelle Goutevin [[BR]]


* Following the modification of the TRUNK since the initial implementation, issues related to the infiltration of water in the soil appeared: 
=> see the initial summary under [attachment: Infiltration_solsgeles_v3.docx​ Soil freezing infiltration problems and suggestions]


==> Several tests have been performed to accound for sub-grid variability of soil freezing in order to limit the reduction of infiltration due to soil freezing (small frost should not modify the infiltration) and to account for the soil moisture (when the soil is dry, the impact of freezing is much lower)  

* Vladislav made a series of tests
 * The results of these tests are:
  * Forcé: https://vesg.ipsl.upmc.fr/thredds/fileServer/work/p529bast/MAPPER/ORC3977_freeze.html
  * Forcé-GSWP3: https://vesg.ipsl.upmc.fr/thredds/fileServer/work/p529bast/MAPPER/ORC3977_gswp3_freeze.html
  * Couplé: https://vesg.ipsl.upmc.fr/thredds/fileServer/work/p529bast/MAPPER/ORC3977_CL4_freeze.html
  * Additional diagnostics can also be found under : [https://orchidas.lsce.ipsl.fr/dev/freeze.3934.php additional_diag_soil_freezing]
 * SUMMARY
  * A first summary of the different tests and their evaluation is gathered under [attachment: Infiltration_sols_gelés.pdf preliminary report]
  * FINAL SUMMARY (APRIL 2017) IS UNDER [attachment: Gel_infiltration_bilan_final_v2.pdf FINAL SUMMARY]