Diagnose vertical velocity when hydrostatic
In the outputs of the Held&Suarez test case the 3D fields "omega" (vertical velocity, in Pa/s) and "W" (vertical velocity, in m/s) are rubbish (NaN for omega and 0 for W), including in the native grid (daily_output_native.nc file)
However W500, OMEGA500 and W850, OMEGA850 , same fields (in principle) but interpolated in the code at 500hPa and 850hPa have reasonable values... maybe OMEGA and W fields sent to output are not or badly computed?