Atmospheric trends over the Arctic Ocean in simulations from the Coordinated Regional Downscaling Experiment (CORDEX) and their driving GCMs

Abstract The Arctic Coordinated Regional Downscaling Experiment (Arctic-CORDEX) uses regional climate models (RCMs) to downscale selected Fifth Coupled Model Intercomparison Project simulations, allowing trend validation and projection on subregional scales. For 1986–2015, the CORDEX seasonal-average near-surface temperature ( tas ), wind speed sfcWind precipitation pr ) snowfall prsn trends are generally consistent with analyses/observations for Ocean regions considered. projected Representative Concentration Pathway 8.5 (RCP8.5) 2016–2100 annual range from 0.03 0.18 K/year. Projected have a large inter-model spread centered around approximately 5.0 × 10 –8 mm/s/year −5.0 mm/s/year, respectively, while summer winter between 0.0 0.4 m/s/year. all variables except , sometimes total precipitation, driving general circulation model (GCM) dominates trends, however there is tendency GCMs underestimate compared RCMs. Subtracting Arctic-Ocean mean reveals consistent, qualitative anomaly pattern in several seasons characterized by greater-than or average central Siberian lesser Atlantic Sector Bering Sea, related sea-ice trends. In particular, strong proportional relationship exists concentration fall anomalies. RCP4.5 annual, multi-model 35–55% of corresponding RCP8.5 most subregions.