Fix location of streamfunction

Co-authored-by: Gregory L. Wagner <[email protected]>

Author: NoraLoose

test/test_zstar_coordinate.jl

@@ -290,7 +290,7 @@ function make_tripolar_test_model(arch; with_wind = false)
 
     # Instead of initializing with random velocities, infer them from a random initial streamfunction
     # to ensure the velocity field is divergence-free at initialization.
-    ψ = Field{Center, Center, Center}(grid)
+    ψ = Field{Face, Face, Center}(grid)
     set!(ψ, rand(size(ψ)...))
     uᵢ = ∂y(ψ)
     vᵢ = -∂x(ψ)