OMIP contribution to CMIP6: experimental and diagnostic protocol for the physical component of the Ocean Model Intercomparison Project.

Abstract

The Ocean Model Intercomparison Project(OMIP) is an endorsed project in the Coupled Model In-tercomparison Project Phase 6 (CMIP6). OMIP addressesCMIP6 science questions, investigating the origins and con-sequences of systematic model biases. It does so by provid-ing a framework for evaluating (including assessment of sys-tematic biases), understanding, and improving ocean, sea-ice, tracer, and biogeochemical components of climate andearth system models contributing to CMIP6. Among theWCRP Grand Challenges in climate science (GCs), OMIPprimarily contributes to the regional sea level change andnear-term (climate/decadal) prediction GCs.OMIP provides (a) an experimental protocol for globalocean/sea-ice models run with a prescribed atmospheric forc-ing; and (b) a protocol for ocean diagnostics to be saved aspart of CMIP6. We focus here on the physical componentof OMIP, with a companion paper (Orr et al., 2016) detail-ing methods for the inert chemistry and interactive biogeo-chemistry. The physical portion of the OMIP experimentalprotocol follows the interannual Coordinated Ocean-ice Ref-erence Experiments (CORE-II). Since 2009, CORE-I (Nor-mal Year Forcing) and CORE-II (Interannual Forcing) havebecome the standard methods to evaluate global ocean/sea-ice simulations and to examine mechanisms for forced oceanclimate variability. The OMIP diagnostic protocol is rele-vant for any ocean model component of CMIP6, includingthe DECK (Diagnostic, Evaluation and Characterization ofKlima experiments), historical simulations, FAFMIP (FluxAnomaly Forced MIP), C4MIP (Coupled Carbon Cycle Cli-mate MIP), DAMIP (Detection and Attribution MIP), DCPP(Decadal Climate Prediction Project), ScenarioMIP, High-ResMIP (High Resolution MIP), as well as the ocean/sea-ice OMIP simulations.