[Dart-dev] DART/branches Revision: 12485

[dart at ucar.edu]

nancy at ucar.edu
2018-04-03 11:05:54 -0600 (Tue, 03 Apr 2018)
239
fix an error in computing model heights if NOT using the
variable mean mass option.  passing in an array of 1.0 values
is NOT the same as omitting the mbar() array - the code uses
a different constant in computing the gas constant terms.




Modified: DART/branches/recam/models/cam-fv/model_mod.f90
===================================================================
--- DART/branches/recam/models/cam-fv/model_mod.f90	2018-04-03 13:54:03 UTC (rev 12484)
+++ DART/branches/recam/models/cam-fv/model_mod.f90	2018-04-03 17:05:54 UTC (rev 12485)
@@ -1469,24 +1469,31 @@
 endif
 
 if (use_variable_mean_mass) then
-  call compute_mean_mass(ens_handle, ens_size, lon_index, lat_index, nlevels, qty, mbar, status1)
+   call compute_mean_mass(ens_handle, ens_size, lon_index, lat_index, nlevels, qty, mbar, status1)
 
-  if (status1 /= 0) then
-     my_status = status1
-     return
-  endif
+   if (status1 /= 0) then
+      my_status = status1
+      return
+   endif
+   !print*, 'mbar', mbar(1,1), mbar(nlevels,1), my_status, status1
+
+   ! compute the height columns for each ensemble member - passing mbar() array in.
+   do imember = 1, ens_size
+      call build_heights(nlevels, surface_pressure(imember), surface_elevation(1), &
+                         tv(:, imember), height_array(:, imember), mbar=mbar(:, imember))
+   enddo
+
 else
-   mbar(:,:) = 1.0_r8
+   ! compute the height columns for each ensemble member - no mbar() argument here.
+   ! (you cannot just pass 1.0 in for the mbar() array; it uses a different gas constant
+   ! in the variable mean mass case.)
+   do imember = 1, ens_size
+      call build_heights(nlevels, surface_pressure(imember), surface_elevation(1), &
+                         tv(:, imember), height_array(:, imember))
+   enddo
 endif
 
-  !print*, 'mbar', mbar(1,1), mbar(nlevels,1), my_status, status1
-! compute the height columns for each ensemble member
-do imember = 1, ens_size
-   call build_heights(nlevels, surface_pressure(imember), surface_elevation(1), &
-                      tv(:, imember), height_array(:, imember), mbar=mbar(:, imember))
-enddo
 
-
 if (debug_level > 100) then
  do imember = 1, ens_size
   print *, ''
@@ -1544,7 +1551,8 @@
 
 !-----------------------------------------------------------------------
 !> Compute column of pressures at the layer midpoints for the given 
-!> surface pressure. 
+!> surface pressure.  This routine IS being called, unlike the others
+!> below.
 !>
 !>@todo FIXME unlike some other things - you could pass in an upper and lower
 !>level number and compute the pressure only at the levels between those.
@@ -1571,7 +1579,7 @@
 
 !-----------------------------------------------------------------------
 !> Compute columns of pressures at the layer interfaces for the given number 
-!> of surface pressures. 
+!> of surface pressures.  CURRENTLY UNUSED.
 !>
 !>@todo FIXME see comment above in cam_p_col_midpts()
 
@@ -1595,7 +1603,9 @@
 
 !-----------------------------------------------------------------------
 !> Compute columns of heights at the layer midpoints for the given number 
-!> of surface pressures and surface elevations.
+!> of surface pressures and surface elevations.  THIS ROUTINE IS CURRENTLY
+!> UNUSED, AND HAS NO PROVISION FOR PASSING DOWN THE VARIABLE MEAN MASS
+!> PARAMETER.
 
 subroutine cam_h_col_midpts(n_levels, surface_pressure, surface_elev, virtual_temp, &
                             height_array)
@@ -1621,7 +1631,8 @@
 
 !-----------------------------------------------------------------------
 !> Compute columns of heights at the layer interfaces for the given number 
-!> of surface pressures. 
+!> of surface pressures.   THIS ROUTINE IS ALSO CURRENTLY UNUSED AND
+!> IN FACT NOT WRITTEN.   FIXME: should these be removed?
 
 subroutine cam_h_col_intfcs(n_levels, surface_pressure, surface_elev, virtual_temp, &
                             height_array)
@@ -2853,6 +2864,11 @@
 ! cam uses a uniform gas constant value, but high top
 ! models like waccm change the gas constant with height.
 ! allow for the calling code to pass in an array of r.
+
+! if mbar() array is present notice that the units are different
+! for the gas constants, so an mbar() array of 1.0s will NOT give
+! the same results as if it isn't present.
+
 if (present(mbar)) then
    r_g0_tv(:) = (universal_gas_constant / (mbar(:)*g0)) * virtual_temp(:)
 else