The GFDL Global Ocean and Sea Ice Model OM4.0: Model Description and Simulation Features. (18th October 2019)

• Record Type: Journal Article
• Authors: Adcroft, Alistair; Anderson, Whit; Balaji, V.; Blanton, Chris; Bushuk, Mitchell; Dufour, Carolina O.; Dunne, John P.; Griffies, Stephen M.; Hallberg, Robert; Harrison, Matthew J.; Held, Isaac M.; Jansen, Malte F.; John, Jasmin G.; Krasting, John P.; Langenhorst, Amy R.; Legg, Sonya; Liang, Zhi; McHugh, Colleen; Radhakrishnan, Aparna; Reichl, Brandon G.; Rosati, Tony; Samuels, Bonita L.; Shao, Andrew; Stouffer, Ronald; Winton, Michael; Wittenberg, Andrew T.; Xiang, Baoqiang; Zadeh, Niki; Zhang, Rong
• Is Part Of: Journal of advances in modeling earth systems. Volume 11:Number 10(2019)
• Page Start: 3167
• Page End: 3211
• Publication Date: 2019-10-18
• Subjects: ocean circulation model -- CORE -- hybrid coordinates; Geological modeling -- Periodicals; Climatology -- Periodicals; Geochemical modeling -- Periodicals; 551.5011
• DOI: 10.1029/2019MS001726
• Languages: English
• ISSNs: 1942-2466

Abstract

Abstract: We document the configuration and emergent simulation features from the Geophysical Fluid Dynamics Laboratory (GFDL) OM4.0 ocean/sea ice model. OM4 serves as the ocean/sea ice component for the GFDL climate and Earth system models. It is also used for climate science research and is contributing to the Coupled Model Intercomparison Project version 6 Ocean Model Intercomparison Project. The ocean component of OM4 uses version 6 of the Modular Ocean Model and the sea ice component uses version 2 of the Sea Ice Simulator, which have identical horizontal grid layouts (Arakawa C‐grid). We follow the Coordinated Ocean‐sea ice Reference Experiments protocol to assess simulation quality across a broad suite of climate‐relevant features. We present results from two versions differing by horizontal grid spacing and physical parameterizations: OM4p5 has nominal 0.5° spacing and includes mesoscale eddy parameterizations and OM4p25 has nominal 0.25° spacing with no mesoscale eddy parameterization. Modular Ocean Model version 6 makes use of a vertical Lagrangian‐remap algorithm that enables general vertical coordinates. We show that use of a hybrid depth‐isopycnal coordinate reduces the middepth ocean warming drift commonly found in pure z * vertical coordinate ocean models. To test the need for the mesoscale eddy parameterization used in OM4p5, we examine the results from a simulation that removes the eddy parameterization. The water mass structure and model drift are physically degraded relative to OM4p5, thus supporting the key role for a mesoscale closure at this resolution. Key Points: Documentation is provided for a new generation of NOAA‐GFDL CMIP6/OMIP ocean ice climate models Dynamical core and physical parameterizations are described and key features of interannual CORE simulations are assessed Using hybrid vertical coordinates reduces spurious ocean heat drift