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GFS physics for CCPP
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Add prognostic cumulus closure description in saSAS #903

Closed lisa-bengtsson closed 2 years ago

lisa-bengtsson commented 2 years ago

This PR introduces an optional closure assumption to the Arakawa-Schubert cloud work function in saSAS cumulus convection, as well as in the GFS shallow convection scheme in where the mass-flux at cloud base is described as the product between updraft area fraction and updraft velocity. The updraft area fraction is given by a prognostic moisture budget equation.

The update is not aimed for UFS coupled prototype 8, but is an option to be explored beyond P8.

In addition to updates in the ccpp/physics submodule, new field_table, and namelist parameters are added in ufs-weather-model.

Issue: https://github.com/NCAR/ccpp-physics/issues/890 Dependency: https://github.com/NOAA-EMC/fv3atm/pull/523

JongilHan66 commented 2 years ago

@lisa-bengtsson I strongly suggest to include "advfac" in both deep and shallow convection schemes, i.e., if(progsigma)then xmb(i) = sigmab(i)((-1.0omegac(i))/grav) => if(progsigma)then xmb(i) = advfac(i)sigmab(i)((-1.0*omegac(i))/grav)

The impact of "advfac" becomes significant in strong wind conditions such as in hurricane and more significant in higher resolution. As I presented in the convection meeting, without "advfac" term you would have a serious degrade in hurricane forecast (especially intensity) in both GFS and HAFS.

lisa-bengtsson commented 2 years ago

Ok, I can add this. We should do some tests on hurricane forecasts with and without this term for the sigmab closure as well. Thanks.