Tr/add get_fields and update_fields to ClimaAtmosSimulation (#1205)

* Add more get_fields to ClimaAtmosSimulation

Add diffuse_fraction, SW_d, LW_d, and cos of the zenith_angle
to get_field on AtmosModelSimulation in Interfacer.jl.

Add get_field methods for the above values in
ClimaAtmosSimulation

Remove safe_div and use anonymous func

Only calculate on first level for diffuse_frac

Add update_field for emissivity in AtmosModelSim

Add emissivity to update_field in the Interfacer,
and add a method definition for it in climaatmos.jl
All 16 bands are set to the same values.

Clamp diffuse_fraction to [0,1]

Remove :co2 from atmos update_field

:co2 is removed from the default AtmosModelSimulation
update_field. The method definition is also removed for
ClimaAtmosSimulation.

Add atmos get_field for :co2

Add a default get_field for :co2 with AtmosModelSimulation,
and a method definition for ClimaAtmosSimulation. Note that this
returns a scalar.

Add new fields to interfacer_tests

Revert to returning zero when dividing by zero

In get_field(::ClimaAtmosSimulation, ::Val{:diffuse_fraction}

* Add air pressure, air temp, and humidity get_field

Add them to the the generic get_field for
AtmosModelSimulations and specific methods
for ClimaAtmosSimulations

* Update Interfacer.md with atmos get_field changes

* Change `cos_zenith_angle` to `cos_zenith`

It is refered to as `cos_zenith` by atmos and
`cos\thetas` by land. This unifies it with one of
the models.
[skip ci]

* Change humidity to specific_humidity for atmos

* Remove not always required fields default get_field

remove from interfacer tests

Author: imreddyTeja

docs/src/interfacer.md

@@ -113,7 +113,7 @@ following properties:
 
 | Coupler name      | Description | Units |
 |-------------------|-------------|-------|
-| `co2`              | global mean co2 | ppm |
+| `emissivity`   | surface emissivity | |
 | `surface_direct_albedo`   | bulk direct surface albedo over the whole surface space | |
 | `surface_diffuse_albedo`   | bulk diffuse surface albedo over the whole surface space | |
 | `surface_temperature` | temperature over the combined surface space | K |
@@ -123,6 +123,31 @@ following properties:
 A function to return the air density of the atmosphere simulation
 extrapolated to the surface, with units of [kg m^-3].
 
+<!-- replace  "full ClimaLand model" with name of coupler sim struct-->
+### AtmosModelSimulation - required functions to run with the full ClimaLand model
+
+Coupling with full `ClimaLand` model requires the following functions, in addition
+to the functions required for coupling with a general `SurfaceModelSimulation`.
+
+- `get_field(::AtmosModelSimulation. ::Val{property})`:
+This getter function must be extended
+for the following properties:
+
+| Coupler name      | Description | Units |
+|-------------------|-------------|-------|
+| `air_pressure`     | air pressure at the bottom cell centers of the atmosphere | Pa |
+| `air_temperature`  | air temperature at the bottom cell centers of the atmosphere | K |
+| `cos_zenith` | cosine of the zenith angle | |
+| `co2`              | global mean co2 | ppm |
+| `diffuse_fraction` | fraction of downwards shortwave flux that is direct | |
+| `specific_humidity`         | specific humidity at the bottom cell centers of the atmosphere| kg kg^-1 |
+| `LW_d`             | downwards longwave flux | W m^-2 |
+| `SW_d`             | downwards shortwave flux | W m^-2 |
+
+Note that `air_temperature`, `air_pressure`, `cos_zenith`, `co2`, `diffuse_fraction`, `LW_d` and
+`SW_d` will not be present in a `ClimaAtmosSimulation` if the model is setup with no radiation.
+Because of this, a `ClimaAtmosSimulation` must have radiation if running with the full `ClimaLand` model.
+
 ### SurfaceModelSimulation - required functions
 Analogously to the `AtmosModelSimulation`, a `SurfaceModelSimulation`
 requires additional functions to those required for a general `ComponentModelSimulation`.

experiments/ClimaEarth/components/atmosphere/climaatmos.jl

@@ -171,12 +171,54 @@ moisture_flux(::Union{CA.EquilMoistModel, CA.NonEquilMoistModel}, integrator) =
 ρq_tot(::Union{CA.EquilMoistModel, CA.NonEquilMoistModel}, integrator) = integrator.u.c.ρq_tot
 
 # extensions required by the Interfacer
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:air_pressure}) =
+    CC.Fields.level(sim.integrator.p.precomputed.ᶜp, 1)
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:air_temperature}) =
+    TD.air_temperature.(
+        sim.integrator.p.params.thermodynamics_params,
+        CC.Fields.level(sim.integrator.p.precomputed.ᶜts, 1),
+    )
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:cos_zenith}) = CC.Fields.array2field(
+    sim.integrator.p.radiation.rrtmgp_model.cos_zenith,
+    CC.Fields.level(axes(sim.integrator.u.c), 1),
+)
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:co2}) =
+    sim.integrator.p.radiation.rrtmgp_model.volume_mixing_ratio_co2[]
+function Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:diffuse_fraction})
+    radiation_model = sim.integrator.p.radiation.rrtmgp_model
+    # only take the first level
+    total_flux_dn = radiation_model.face_sw_flux_dn[1, :]
+    lowest_face_space = CC.Spaces.level(axes(sim.integrator.u.f), CC.Utilities.half)
+    if radiation_model.radiation_mode isa CA.RRTMGPInterface.GrayRadiation
+        diffuse_fraction = zero(total_flux_dn)
+    else
+        direct_flux_dn = radiation_model.face_sw_direct_flux_dn[1, :]
+        FT = eltype(total_flux_dn)
+        diffuse_fraction =
+            clamp.(
+                ((x, y) -> y > zero(y) ? x / y : zero(y)).(total_flux_dn .- direct_flux_dn, total_flux_dn),
+                zero(FT),
+                one(FT),
+            )
+    end
+    return CC.Fields.array2field(diffuse_fraction, lowest_face_space)
+end
 Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:liquid_precipitation}) =
     surface_rain_flux(sim.integrator.p.atmos.moisture_model, sim.integrator)
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:LW_d}) = CC.Fields.level(
+    CC.Fields.array2field(sim.integrator.p.radiation.rrtmgp_model.face_lw_flux_dn, axes(sim.integrator.u.f)),
+    CC.Utilities.half,
+)
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:specific_humidity}) =
+    CC.Fields.level(sim.integrator.u.c.ρq_tot ./ sim.integrator.u.c.ρ, 1)
 Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:radiative_energy_flux_sfc}) =
     surface_radiation_flux(sim.integrator.p.atmos.radiation_mode, sim.integrator)
 Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:snow_precipitation}) =
     surface_snow_flux(sim.integrator.p.atmos.moisture_model, sim.integrator)
+Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:SW_d}) = CC.Fields.level(
+    CC.Fields.array2field(sim.integrator.p.radiation.rrtmgp_model.face_sw_flux_dn, axes(sim.integrator.u.f)),
+    CC.Utilities.half,
+)
 Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:turbulent_energy_flux}) =
     CC.Geometry.WVector.(sim.integrator.p.precomputed.sfc_conditions.ρ_flux_h_tot)
 Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:turbulent_moisture_flux}) =
@@ -201,15 +243,12 @@ function Interfacer.get_field(sim::ClimaAtmosSimulation, ::Val{:uv_int})
     return @. StaticArrays.SVector(uₕ_int.components.data.:1, uₕ_int.components.data.:2)
 end
 
-function Interfacer.update_field!(atmos_sim::ClimaAtmosSimulation, ::Val{:co2}, field)
-    if atmos_sim.integrator.p.atmos.radiation_mode isa CA.RRTMGPI.GrayRadiation
-        @warn("Gray radiation model initialized, skipping CO2 update", maxlog = 1)
-        return
-    else
-        atmos_sim.integrator.p.radiation.rrtmgp_model.volume_mixing_ratio_co2 .= Statistics.mean(parent(field))
-    end
-end
 # extensions required by the Interfacer
+function Interfacer.update_field!(sim::ClimaAtmosSimulation, ::Val{:emissivity}, field)
+    # sets all 16 bands (rows) to the same values
+    sim.integrator.p.radiation.rrtmgp_model.surface_emissivity .=
+        reshape(CC.Fields.field2array(field), 1, length(parent(field)))
+end
 function Interfacer.update_field!(sim::ClimaAtmosSimulation, ::Val{:surface_direct_albedo}, field)
     sim.integrator.p.radiation.rrtmgp_model.direct_sw_surface_albedo .=
         reshape(CC.Fields.field2array(field), 1, length(parent(field)))

src/Interfacer.jl

@@ -214,7 +214,7 @@ If it isn't extended, the field won't be updated and a warning will be raised.
 update_field!(
     sim::AtmosModelSimulation,
     val::Union{
-        Val{:co2},
+        Val{:emissivity},
         Val{:surface_direct_albedo},
         Val{:surface_diffuse_albedo},
         Val{:surface_temperature},

test/field_exchanger_tests.jl

@@ -93,7 +93,6 @@ end
 function Interfacer.update_field!(sim::TestAtmosSimulation, ::Val{:roughness_momentum}, field)
     parent(sim.cache.roughness_momentum) .= parent(field)
 end
-Interfacer.update_field!(sim::TestAtmosSimulation, ::Val{:co2}, field) = nothing
 Interfacer.update_field!(sim::TestAtmosSimulation, ::Val{:surface_temperature}, field) = nothing
 Interfacer.update_field!(sim::TestAtmosSimulation, ::Val{:roughness_buoyancy}, field) = nothing
 Interfacer.update_field!(sim::TestAtmosSimulation, ::Val{:beta}, field) = nothing

test/interfacer_tests.jl

@@ -209,7 +209,7 @@ end
     sim = DummySimulation4(space)
 
     # Test that update_field! gives correct warnings for unextended fields
-    for value in (:co2, :surface_direct_albedo, :surface_diffuse_albedo, :surface_temperature, :turbulent_fluxes)
+    for value in (:emissivity, :surface_direct_albedo, :surface_diffuse_albedo, :surface_temperature, :turbulent_fluxes)
         val = Val(value)
         @test_logs (
             :warn,