Daohua, BiDix, Martin RMarsland, S JO'Farrell, S PSullivan, ArnoldBodman, RogerLaw, RachelHarman, IanSrbinovsky, JhanRashid, Harun AHeerdegen, Aidan2023-10-152023-10-152206-5865http://hdl.handle.net/1885/303295A new version of the Australian Community Climate and Earth System Simulator coupled model, ACCESS-CM2, has been developed for a wide range of climate modelling research and applications. In particular, ACCESS-CM2 is one of Australia's contributions to the World Climate Research Programme's Coupled Model Intercomparison Project Phase 6 (CMIP6). Compared with the ACCESS1.3 model used for our CMIP5 submission, all model components have been upgraded as well as the coupling framework (OASIS3-MCT) and experiment control system (Rose/Cylc). The component models are: UM10.6 GA7.1 for the atmosphere, CABLE2.5 for the land surface, MOM5 for the ocean, and CICE5.1.2 for the sea ice. This paper describes the model configuration of ACCESS-CM2, documents the experimental set up, and assesses the model performance for the preindustrial spin-up simulation in comparison against (reconstructed) observations and ACCESS1.3 results. While the performance of the two generations of the ACCESS coupled model is largely comparable, ACCESS-CM2 shows better global hydrological balance, more realistic ocean water properties (in terms of spatial distribution) and meridional overturning circulation in the Southern Ocean but a poorer simulation of the Antarctic sea ice and a larger energy imbalance at the top of atmosphere. This energy imbalance reflects a noticeable warming trend of the global ocean over the spin-up period.This project is jointly funded through CSIRO and the Earth Systems and Climate Change Hub of the Australian Government’s National Environmental Science Program.application/pdfen-AU© 2020 The authorshttp://creativecommons.org/licenses/ by-nc-nd/4.0/ACCESS-CM2climate changeclimate simulationCMIP6,coupled climate modelevaluationgreen house gasesphysical configurationpreindustrial spin-uptuning and debugging202010.1071/ES190402022-08-14Creative Commons Attribution licence