An evaluation of the E3SMv1 Arctic ocean and sea-ice regionally refined model

Abstract. The Energy Exascale Earth System Model (E3SM) is a state-of-the-science system model (ESM) with the ability to focus horizontal resolution of its multiple components in specific areas. Regionally refined global ESMs are motivated by need explicitly resolve, rather than parameterize, relevant physics within regions resolution, while offering significant computational cost savings relative respective configurations high-resolution (HR) everywhere on globe. In this paper, we document results from first Arctic regionally E3SM configuration for ocean and sea-ice (E3SM-Arctic-OSI), employing data-based atmosphere, land, hydrology components. Our aim an improved representation coupled state, variability trends, exchanges mass property fluxes between sub-Arctic. We find that E3SM-Arctic-OSI increases realism simulated conditions compared similar low-resolution simulation without regional refinement (E3SM-LR-OSI). particular, through main gateways greatly respect E3SM-LR-OSI. Other aspects, such as freshwater content also satisfactorily simulated. Yet, other features, upper-ocean stratification thickness distribution, further improvements, involving either more advanced parameterizations, tuning, or additional grid refinements. Overall, offers E3SM-LR-OSI, at fraction (15 %) comparable configurations, permitting lower-latitude oceans cannot be directly accounted models.