Height-resolved tendency of convective wet deposition is not correctly diagnosed, passed on and used
Posted by David Neubauer 11/12/2021 https://redmine.hammoz.ethz.ch/issues/807
Several problems exist, none of them severe.
- For convective clouds, the tendency of wet deposition computed in mo_ham_wetdep only includes in-cloud wet deposition fluxes (including evaporation/sublimation of convective precipitation) but it misses below-cloud wet deposition fluxes (including evaporation/sublimation of convective precipitation). Since the vertically integrated convective wet deposition flux is used in SUBROUTINE xt_conv_massfix to actually add the convective wet deposition fluxes the model tendencies, and this flux is not affected but includes both in-cloud and below cloud fluxes, this has no impact currently. The wet deposition diagnostic in the output is correct since it is based on vertically-integrated wet deposition fluxes, not the height-resolved wet deposition tendencies.
- In SUBROUTINE cudtdq in mo_cufluxdts, the tendency of convective wet deposition, computed in a submodel of SUBROUTINE cuflx is set 0 as the convective tracer tendency pxtte_cnv is set to 0 at the beginning of cudtdq. Furthermore, there is "vanilla" non-ham code which assigns the convective tracer fluxes to pxtte_cnv instead of adding them to pxtte_cnv, therefore overwriting the tendency of convective wet deposition. Since the vertically integrated convective wet deposition flux is used in SUBROUTINE xt_conv_massfix to actually add the convective wet deposition fluxes the model tendencies, and this flux is not affected but includes both in-cloud and below cloud fluxes, this has no impact currently.
- In SUBROUTINE xt_conv_massfix the vertically integrated convective wet deposition flux is added to the tracer mass conservation fix of the convective tendencies. This does indeed conserve tracer mass and add the 'net effect' of wet deposition to the model tendencies. However, the mass conservation fix in SUBROUTINE xt_conv_massfix is made such that the final tendencies agree with the tendencies of convection only, not convection + wet deposition. Therefore wet deposition tendencies may be placed at levels where no wet deposition occurs, may be missing at levels where it actually occurs and the strength of the wet deposition tendencies in a level does not reflect what was computed in mo_ham_wetdep (only in a vertically integrated sense, but not in height-resolved sense).
Edited by Anne Kubin