Ocean vertical velocities and fluxes would naturally be held on half levels. In CMIP5 & 6 they are requested on "model levels". In CMIP5, some interpret this as full levels, others have put the data on half levels, but have been obliged to add artificial bounds to satisfy requirements.
This isssue was detected in CMIP6, but too late to do more than add an advisory note to the relevant variables.
See https://github.com/cmip6dr/CMIP6_DataRequest_VariableDefinitions/issues/201
Ocean vertical velocities and fluxes would naturally be held on half levels. In CMIP5 & 6 they are requested on "model levels". In CMIP5, some interpret this as full levels, others have put the data on half levels, but have been obliged to add artificial bounds to satisfy requirements.
This isssue was detected in CMIP6, but too late to do more than add an advisory note to the relevant variables.