Conditionally use high res version of SST/SIC

Following CliMA/ClimaArtifacts#45, we have a
thinned down artifact that can be automatically downloaded if the higher
resolution version is not available.

Author: Sbozzolo

NEWS.md

@@ -0,0 +1,15 @@
+ClimaCoupler.jl Release Notes
+============================
+
+`main`
+-------
+
+### ClimaEarth features
+
+### Sea-surface temperature and sea ice concentration data can now be automatically downloaded
+
+Sea-surface temperature and sea ice concentration require external files. Now, a
+low-resolution version of such files is automatically downloaded when a
+higher-resolution version is not available. Please, refer to
+[ClimaArtifacts](https://github.com/CliMA/ClimaArtifacts) for more information.
+

Project.toml

@@ -4,6 +4,7 @@ authors = ["CliMA Contributors <clima-software@caltech.edu>"]
 version = "0.1.1"
 
 [deps]
+Artifacts = "56f22d72-fd6d-98f1-02f0-08ddc0907c33"
 ClimaComms = "3a4d1b5c-c61d-41fd-a00a-5873ba7a1b0d"
 ClimaCore = "d414da3d-4745-48bb-8d80-42e94e092884"
 ClimaCoreTempestRemap = "d934ef94-cdd4-4710-83d6-720549644b70"
@@ -17,6 +18,7 @@ SurfaceFluxes = "49b00bb7-8bd4-4f2b-b78c-51cd0450215f"
 Thermodynamics = "b60c26fb-14c3-4610-9d3e-2d17fe7ff00c"
 
 [compat]
+Artifacts = "1"
 ClimaComms = "0.5.6, 0.6"
 ClimaCore = "0.14.6"
 ClimaCoreTempestRemap = "0.3"

experiments/ClimaEarth/Artifacts.toml

@@ -22,4 +22,11 @@ git-tree-sha1 = "7486bf32e9352493f69364aead26f01eaf90d2af"
 git-tree-sha1 = "945e31f8028a581f7e8435cb691462124484567a"
 
 [historical_sst_sic]
-git-tree-sha1 = "c4f82cd33fb26513ee45bff78330c6b606630fa5"
+git-tree-sha1 = "0d30d71a6f9b6548fe7395ca647e853ec36d1699"
+
+[historical_sst_sic_lowres]
+git-tree-sha1 = "7f7b6d4ae6055c4c2b6a6dfba5be8b4e6ca1b0be"
+
+    [[historical_sst_sic_lowres.download]]
+    sha256 = "b68c0ce6ea682c38e29cb87c9c6ced6736ecac32d0d32dbaba78beb66046a06c"
+    url = "https://caltech.box.com/shared/static/ufnesb00zkvlc3sxzhnnmqc3zbatxkb9.gz"

experiments/ClimaEarth/run_amip.jl

@@ -173,8 +173,24 @@ The data files are downloaded from the `ClimaCoupler` artifacts directory. If th
 original sources.
 =#
 include(joinpath(pkgdir(ClimaCoupler), "artifacts", "artifact_funcs.jl"))
-sst_data = joinpath(@clima_artifact("historical_sst_sic", comms_ctx), "MODEL.SST.HAD187001-198110.OI198111-202206.nc")
-sic_data = joinpath(@clima_artifact("historical_sst_sic", comms_ctx), "MODEL.ICE.HAD187001-198110.OI198111-202206.nc")
+
+if Utilities.artifact_exists("historical_sst_sic")
+    sst_data =
+        joinpath(@clima_artifact("historical_sst_sic", comms_ctx), "MODEL.SST.HAD187001-198110.OI198111-202206.nc")
+    sic_data =
+        joinpath(@clima_artifact("historical_sst_sic", comms_ctx), "MODEL.ICE.HAD187001-198110.OI198111-202206.nc")
+else
+    ClimaComms.iamroot(comms_ctx) &&
+        @warn "Using lowres sst sic. If you want the higher resolution version, you have to obtain it from ClimaArtifacts"
+    sst_data = joinpath(
+        @clima_artifact("historical_sst_sic_lowres", comms_ctx),
+        "MODEL.SST.HAD187001-198110.OI198111-202206_lowres.nc",
+    )
+    sic_data = joinpath(
+        @clima_artifact("historical_sst_sic_lowres", comms_ctx),
+        "MODEL.ICE.HAD187001-198110.OI198111-202206_lowres.nc",
+    )
+end
 co2_data = joinpath(co2_dataset_path(), "mauna_loa_co2.nc")
 land_mask_data = joinpath(mask_dataset_path(), "seamask.nc")
 

src/Utilities.jl

@@ -6,12 +6,31 @@ modules in the coupler.
 """
 module Utilities
 
+import Artifacts
 import ClimaComms
 import ClimaCore as CC
 import Logging
 
 export swap_space!
 
+"""
+    artifact_exists(name)
+
+Return whether the artifact with the given name exists and is available to use.
+"""
+function artifact_exists(name)
+    # There seems to be no easy way to determine if an artifact exists from the name
+    # only...
+    return try
+        # We need to macroexpand because we only want to resolve @artifact_str when
+        # we call this function
+        @macroexpand Artifacts.@artifact_str(name)
+        true
+    catch error
+        false
+    end
+end
+
 """
     swap_space!(space_out::CC.Spaces.AbstractSpace, field_in::CC.Fields.Field)