Based on the Coupled Model Intercomparison Project Phase 6 (CMIP6), the paper evaluates the performance of the state-of-the-art climate model BCC-CSM2-MR in simulating the Arctic sea ice and the Arctic climate using sea surface temperature and sea ice density data from the Hadley Center and the reanalyzed data from National Center for Environmental Prediction and National Center for Atmospheric Research and further projected their potential changes in a future warmer world under Shared Socio-economic Path (SSP). The results show that the BCC-CSM2-MR model can better reproduce the multi-year average spatial distribution of Arctic sea ice concentration, near-surface atmospheric mean temperature and sea surface temperature. However, the simulation has a certain deviation from the observation of the atmospheric temperature in the Arctic, which possible leads to differences in the simulation of sea ice in the corresponding areas. In the 21st century, the Arctic sea ice range is projected to decrease continuously, with a significant reduction in September and a relatively weaker trend in March. In March, the atmospheric temperature would show a consistent increase over most of the Arctic except the North Atlantic. The increasement of atmosphere temperature is weaker in September than that in March. Unlike the atmosphere temperature, the sea surface temperature would both increase in March and September in most parts of the Arctic except the Labrador Sea. The increasement of sea surface temperature is much greater in September than that in March.

Keywords： Arctic ; Sea ice intensity ; Simulation ; Shared Socio-economic Path (SSP) ; Projection