output debug diagnostics when there is nan

src/callbacks/get_callbacks.jl

@@ -152,7 +152,29 @@ function get_diagnostics(parsed_args, atmos_model, Y, p, t_start, dt)
         @info "$writer_str: $diags_outputs"
     end
 
-    return diagnostics, writers
+    function WhenRSUTIsNaN(integrator)
+        nlevels = Spaces.nlevels(axes(integrator.u.c))
+        return any(isnan, parent(Fields.level(
+            Fields.array2field(
+                integrator.p.radiation.radiation_model.face_sw_flux_up,
+                axes(integrator.u.f),
+            ),
+            nlevels + ClimaCore.half,
+        )))
+    end
+
+    short_names_debug = ["ta", "hus", "wa"]
+
+    debug_diagnostics = [
+        CAD.ScheduledDiagnostic(
+            variable = CAD.get_diagnostic_variable(short_name),
+            compute_schedule_func = WhenRSUTIsNaN,
+            output_schedule_func = WhenRSUTIsNaN,
+            output_writer = netcdf_writer,
+        ) for short_name in short_names_debug
+    ]
+
+    return [diagnostics..., debug_diagnostics...], writers
 end
 
 function get_callbacks(config, sim_info, atmos, params, Y, p, t_start)