ACCESS-OM2 v1.0: a global ocean-sea ice model at three resolutions

• Published in: Geoscientific Model Development
• Main Authors: Kiss, A, McC Hogg, A, Hannah, N, Boeira Dias, FB, Brassington, GB, Chamberlain, MA, Chapman, C, Dobrohotoff, P, Domingues, CM, Duran, ER, England, MH, Fiedler, R, Griffies, SM, Heerdegen, A, Heil, P, Holmes, RM, Klocker, A, Marsland, SJ, Morrison, AK, Munroe, J, Nikurashin, M, Oke, PR, Pilo, GS, Richet, O, Savita, A, Spence, P, Stewart, KD, Ward, ML, Wu, F, Zhang, X
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus GmbH 2020
• Subjects: Earth Sciences; Other earth sciences; Other earth sciences not elsewhere classified; Sea ice
• Online Access: https://doi.org/10.5194/gmd-13-401-2020; http://ecite.utas.edu.au/139718

We introduce ACCESS-OM2, a new version of the oceansea ice model of the Australian Community Climate and Earth System Simulator.ACCESS-OM2 is driven by a prescribed atmosphere (JRA55-do) but has been designed to form the oceansea ice component of the fully coupled (atmospherelandoceansea ice) ACCESS-CM2 model.Importantly, the model is available at three different horizontal resolutions: a coarse resolution (nominally 1 ∘ horizontal grid spacing), an eddy-permitting resolution (nominally 0.25 ∘ ), and an eddy-rich resolution (0.1 ∘ with 75 vertical levels); the eddy-rich model is designed to be incorporated into the Bluelink operational ocean prediction and reanalysis system.The different resolutions have been developed simultaneously, both to allow for testing at lower resolutions and to permit comparison across resolutions.In this paper, the model is introduced and the individual components are documented.The model performance is evaluated across the three different resolutions, highlighting the relative advantages and disadvantages of running oceansea ice models at higher resolution.We find that higher resolution is an advantage in resolving flow through small straits, the structure of western boundary currents, and the abyssal overturning cell but that there is scope for improvements in sub-grid-scale parameterizations at the highest resolution.