Quantification of The Performance of CMIP6 Models for Dynamic Downscaling in The North Pacific and Northwest Pacific Oceans

Abstract

Selecting a reliable global climate model as the driving forcing in simulations with dynamic downscaling is critical for obtaining a reliable regional ocean climate. With respect to their accuracy in providing physical quantities and long-term trends, we quantify the performances of 17 models from the Coupled Model Inter-comparison Project Phase 6 (CMIP6) over the North Pacific (NP) and Northwest Pacific (NWP) oceans for 1979–2014. Based on normalized evaluation measures, each model’s performance for a physical quantity is mainly quantified by the performance score (PS), which ranges from 0 to 100. Overall, the CMIP6 models reasonably reproduce the physical quantities of the driving variables and the warming ocean heat content and temperature trends. However, their performances significantly depend on the variables and region analyzed. The EC-Earth-Veg and CNRM-CM6-1 models show the best performances for the NP and NWP oceans, respectively, with the highest PS values of 85.89 and 76.97, respectively. The EC-Earth3 model series are less sensitive to the driving variables in the NP ocean, as reflected in their PS. The model performance is significantly dependent on the driving variables in the NWP ocean. Nevertheless, providing a better physical quantity does not correlate with a better performance for trend. However, MRI-ESM2-0 model shows a high performance for the physical quantity in the NWP ocean with warming trends similar to references, and it could thus be used as an appropriate driving forcing in dynamic downscaling of this ocean. This study provides objective information for studies involving dynamic downscaling of the NP and NWP oceans.

Near-Future Projection of Sea Surface Winds in Northwest Pacific Ocean Based on a CMIP6 Multi-Model Ensemble

“…Notably, IPSL-CM6A-LR, MIROC6, and ACCES-CM2 exhibit outstanding individual skill, reinforcing the utility of MMM. Furthermore, in a previous study [20], the authors ranked ACCES-CM2 as the best for the wind variable in the NWP based on a performance score using the normalized RMSD and Taylor skill score. Therefore, the findings of this study also provide information about the alternative best choices aside from ACCES-CM2 in terms of individual CMIP6 model usage, as the earlier study did not include considerations for IPSL-CM6A-LR and MIROC6.…”

“…Currently, the best tool to investigate future conditions of oceanic and atmospheric processes is the latest version of Coupled Model Intercomparison Project Phase 6 (CMIP6) [18] since it provides projections based on different Shared Socio-Economic Pathways (SSPs) and distinct radiative forcing scenarios. Previous studies have assessed the results of CMIP6 models in the NWP region, such as [19,20]. The authors mostly focused on the performance models, which suggested that CMIP6 models generally have sufficiently good skills to reproduce the annual trends and variability of atmospheric or oceanic variables such as surface winds and ocean temperatures.…”