Add omega support to barotropic gyre

Author: cbegeman

polaris/tasks/ocean/barotropic_gyre/forward.yaml

@@ -81,13 +81,16 @@ Omega:
       UsePointerFile: false
       Filename: output.nc
       Mode: write
-      IfExists: append
+      IfExists: replace
       Precision: double
       Freq: {{ output_interval }}
       FreqUnits: {{ output_interval_units }}
       UseStartEnd: false
       Contents:
       - State
       - SshCell
+      - WindStressZonal
+      - WindStressMeridional
+      - RelVortVertex
       FileFreq: 9999
       FileFreqUnits: years