Merge #2190

2190: Try to fix moist gpu example r=charleskawczynski a=charleskawczynski

This PR fixes the next breaking piece, blocking us from #1980. Closes #2191.

Co-authored-by: Charles Kawczynski <kawczynski.charles@gmail.com>

src/prognostic_equations/vertical_diffusion_boundary_layer.jl

@@ -84,16 +84,14 @@ function vertical_diffusion_boundary_layer_tendency!(
 
     FT = eltype(Y)
     interior_uₕ = Fields.level(Y.c.uₕ, 1)
-    interior_coordinates = Fields.level(Fields.coordinate_field(Y.c), 1)
-    z_surface =
-        Fields.level(Fields.coordinate_field(Y.f).z[colidx], Fields.half)
     ᶠp = ᶠρK_E = p.ᶠtemp_scalar
     @. ᶠp[colidx] = ᶠinterp(ᶜp[colidx])
+    ᶜΔz_surface = Fields.Δz_field(interior_uₕ)
     @. ᶠρK_E[colidx] =
         ᶠinterp(Y.c.ρ[colidx]) * eddy_diffusivity_coefficient(
             C_E,
             norm(interior_uₕ[colidx]),
-            interior_coordinates.z[colidx] - z_surface,
+            ᶜΔz_surface[colidx] / 2,
             ᶠp[colidx],
         )