Arctic Ocean Simulations in the CMIP6 Ocean Model Intercomparison Project (OMIP)

Abstract

Abstract. Arctic Ocean simulations in 19 global ocean-sea ice models participating in the Ocean Model Intercomparison Project (OMIP) of the CMIP6 are evaluated in this paper. Our results indicate that no significant improvements were achieved in the Arctic Ocean simulations from the previous Coordinated Ocean-ice Reference Experiments phase II (CORE-II) to the current OMIP. Large model biases and inter-model spread exist in the simulated mean state of the halocline and Atlantic Water layer in the OMIP models. Most of the OMIP models suffer from too thick and deep Atlantic Water layer, too deep halocline base, and large fresh biases in the halocline. The OMIP models largely agree on the inter-annual and decadal variability of the Arctic Ocean freshwater content and volume/heat/freshwater transports through the Arctic Ocean gateways. The models can reproduce observed changes in volume, heat and freshwater transports through the gateways except for the Bering Strait. Overall, the performance of the Arctic Ocean simulations is similar between the CORE2-forced OMIP-1 and JRA55-do-forced OMIP-2.

Arctic Ocean simulations in the CMIP6 Ocean Model Intercomparison Project (OMIP)

“…Code availability. Matlab code used to process data and generate figures is available at https://doi.org/10.5281/zenodo.7808054 (Shu, 2022).…”

Arctic freshwater impact on the Atlantic Meridional Overturning Circulation: status and prospects

“…Support is needed to facilitate and accelerate this pipeline.Extend and refine dynamically consistent reanalyses, such as ECCOv4r4. These state estimates are our best (albeit imperfect and provisional) tools to track and understand the basin-scale, decadal stratification and circulation changes.Study and refine coupled climate models to resolve Arctic Ocean biases, especially in the Atlantic Water, the halocline and the surface Polar Water layer, and thereby decrease the model spread in projected salinity changes [24,27]. Perform consistent, robust budget analyses (like those in figures 2, 5 and 6).…”

“…Study and refine coupled climate models to resolve Arctic Ocean biases, especially in the Atlantic Water, the halocline and the surface Polar Water layer, and thereby decrease the model spread in projected salinity changes [24,27].…”

“…The projected increase in atmospheric moisture flux convergence is moderately well established [20–23], but the anticipated changes to the marine outflows are poorly known. Moreover, well-known, stubborn biases exist in the Arctic Oceans of CMIP6 models [11,24–27].…”