t1,q1,z1,wind in sfc_diff

[JongilHan66]

Could you let me know where t1, q1, z1, and wind (air temperature, specific humidity, height, and wind speed at the lowest model layer) are obtained before executing sfc_diff.f? I consider using those values at the first layer above 10*z0 (z0: surface roughness) for sfc_diff.f rather than those at the lowest model layer.

[climbfuji]

Hi Jongil, I am looking in sfc_diff.meta and find the following:

[t1]
  standard_name = air_temperature_at_lowest_model_layer
  long_name = 1st model layer air temperature
  units = K
  dimensions = (horizontal_loop_extent)
  type = real
  kind = kind_phys
  intent = in
  optional = F

Since this variable must exist "somewhere" in the host model, I am looking in GFS_typedefs.meta and find

[tgrs(:,1)]
  standard_name = air_temperature_at_lowest_model_layer
  long_name = mean temperature at lowest model layer
  units = K
  dimensions = (horizontal_loop_extent)
  type = real
  kind = kind_phys

in the metadata table for the GFS_statein_type DDT.

Thus, t1 is nothing else than the lowest level of the full air temperature model state, Statein%tgrs(:,1). Similar for u1, v1, z1.

Does this answer your question?

[JongilHan66]

Hi Dom,

Thank you. How about surface roughness length (zorl)? Where is it obtained? To get 'tair' (air temperature at the first model layer above 10 times zorl), I need both zorl and tgrs(:,:).

[climbfuji]

That depends which zorl. Recall you are in the part of the code where the surface composites are treated independently. If you want zorl_ice, zorl_ocean (which is really water, because it includes lake), and zorl_land, then you already have them available in sfc_diff:

[z0rl_wat]
  standard_name = surface_roughness_length_over_ocean_interstitial
  long_name = surface roughness length over ocean (temporary use as interstitial)
  units = cm
  dimensions = (horizontal_loop_extent)
  type = real
  kind = kind_phys
  intent = inout
  optional = F
[z0rl_lnd]
  standard_name = surface_roughness_length_over_land_interstitial
  long_name = surface roughness length over land  (temporary use as interstitial)
  units = cm
  dimensions = (horizontal_loop_extent)
  type = real
  kind = kind_phys
  intent = inout
  optional = F
[z0rl_ice]
  standard_name = surface_roughness_length_over_ice_interstitial
  long_name = surface roughness length over ice   (temporary use as interstitial)
  units = cm
  dimensions = (horizontal_loop_extent)
  type = real
  kind = kind_phys
  intent = inout
  optional = F

[JongilHan66]

As I said, to get 'tair' (air temperature at the first model layer above 10 times zorl which can be the second model layer), I need both zorl and tgrs(:,:) [NOT tgrs(:,1)]. In GFS_typedefs.F90, we have tgrs(:,:) but we don't have zorl. In sfc_diff.f, we have zorl but don't have tgrs(:,:).

[climbfuji]

Then you need to simply pass in the entire tgrs array instead of just the slice tgrs(:,1). In sfc_diff.meta, replace

[t1]
  standard_name = air_temperature_at_lowest_model_layer
  long_name = 1st model layer air temperature
  units = K
  dimensions = (horizontal_loop_extent)
  type = real
  kind = kind_phys
  intent = in
  optional = F

with

[tair]
  standard_name = air_temperature
  long_name = model layer mean temperature
  units = K
  dimensions = (horizontal_loop_extent,vertical_dimension)
  type = real
  kind = kind_phys
  intent = in
  optional = F

In sfc_diff.f, replace the intent declaration for t1 with the appropriate one for tair and use tair for what you need to do. Places that use t1(i) in the code then become tair(i,1).

[JongilHan66]

I see. Thanks very much!!