Specific water species handling from physics_update needs to be implemented

[cacraigucar]

Inside of CAM's version of physics_update, there are two sections which impact water species, but have not been implemented in CAM-SIMA yet. These sections are:

          ! don't call qneg3 for number concentration variables
          if (m /= ixnumice  .and.  m /= ixnumliq .and. &
              m /= ixnumrain .and.  m /= ixnumsnow ) then
             call qneg3(trim(ptend%name), state%lchnk, ncol, state%psetcols, pver, m, m, qmin(m:m), state%q(:,1:pver,m:m))
          else
             do k = ptend%top_level, ptend%bot_level
                ! checks for number concentration
                state%q(:ncol,k,m) = max(1.e-12_r8,state%q(:ncol,k,m))
                state%q(:ncol,k,m) = min(1.e10_r8,state%q(:ncol,k,m))
             end do
          end if

    ! Enforce a minimum non-zero value.
    if (ixcldliq > 1) then
       if(ptend%lq(ixcldliq)) then
#ifdef PERGRO
          if ( any(ptend%name == pergro_cldlim_names) ) &
               call state_cnst_min_nz(1.e-12_r8, ixcldliq, ixnumliq)
#endif
          if ( any(ptend%name == cldlim_names) ) &
               call state_cnst_min_nz(1.e-36_r8, ixcldliq, ixnumliq)
       end if
    end if

    if (ixcldice > 1) then
       if(ptend%lq(ixcldice)) then
#ifdef PERGRO
          if ( any(ptend%name == pergro_cldlim_names) ) &
               call state_cnst_min_nz(1.e-12_r8, ixcldice, ixnumice)
#endif
          if ( any(ptend%name == cldlim_names) ) &
               call state_cnst_min_nz(1.e-36_r8, ixcldice, ixnumice)
       end if
    end if

Without these changes, a test run of ZM code using snapshots generated with the unaltered physics_update code gives the following differences:

 Variable                                          # Diffs  Max Diff   Max Diff loc (rank, col, lev)
 --------                                          -------  --------   -----------------------------
 air_temperature                                      1279  0.22E-15   (0,383,25)                                                   
 geopotential_height_wrt_surface                      1647  0.44E-15   (0,427,29)                                                   
 geopotential_height_wrt_surface_at_interface         1612  0.43E-15   (0,429,31)                                                   
 tendency_of_air_temperature_due_to_model_physics     2041  0.95E-15   (0,324,26)                                                   
 cnst_NUMICE                                          6548  0.30E-11   (0,36,28)                                                    
cloud_ice_mixing_ratio_wrt_moist_air_and_condensed_water
                                                       660  0.96E-36   (0,134,32)                                                   
water_vapor_mixing_ratio_wrt_moist_air_and_condensed_water
                                                       790  0.30E-15   (0,146,29)                                                   
 cnst_NUMLIQ                                          9700  0.11E-09   (0,126,29)                                                   
 cnst_NUMSNO                                          5463  0.10E-11   (0,31,26)                                                    
 cnst_NUMRAI                                          6023  0.32E-13   (0,141,21)                                                   
cloud_liquid_water_mixing_ratio_wrt_moist_air_and_condensed_water
                                                      7072  0.10E-35   (0,45,21)                                                    
 ********** End Physics Check Data Results **********

With the above three sections of code commented out in the CAM run which made the snapshot files, the identical ZM code gives the following differences:

  Variable                                          # Diffs  Max Diff   Max Diff loc (rank, col, lev)
 --------                                          -------  --------   -----------------------------
 air_temperature                                      1248  0.22E-15   (0,419,26)                                                   
 geopotential_height_wrt_surface                      1858  0.44E-15   (0,7,27)                                                     
 geopotential_height_wrt_surface_at_interface         1813  0.44E-15   (0,440,31)                                                   
 tendency_of_air_temperature_due_to_model_physics     2109  0.11E-14   (0,47,23)                                                    
water_vapor_mixing_ratio_wrt_moist_air_and_condensed_water
                                                       706  0.35E-15   (0,271,30)