BCC-CSM2-MR模式对北极海冰和气候的模拟及预估

Simulation and projection of Arctic sea ice and climate by BCC-CSM2-MR

基于第六次耦合模式比较计划(CMIP6),使用新一代全球模式BCC-CSM2-MR的历史试验和未来共享社会经济路径(SSPs)数据,依据Hadley中心的海表面温度和海冰密集度数据及NCEP/NCAR I再分析资料,评估了BCCCSM2-MR模式对北极海冰及北极气候的模拟能力,并对未来变化进行了预估。结果表明:BCC-CSM2-MR模式可以较好再现北极海冰密集度、近地层大气平均温度和海表温度的多年平均空间分布特征。但模式对北极局地大气平均温度模拟存在一定偏差,可能在一定程度上导致相应地区海冰的模拟存在差异。21世纪,北极海冰范围持续减少,9月减少趋势显著,3月减少趋势相对较弱。3月北极大部地区表现为一致的增温,仅在北大西洋局部出现一定程度的降温,9月北极大气增温幅度弱于3月。与地表平均温度不同,3月和9月的北极大部地区海表温度均出现增加,且9月海表温度的增幅大于3月,仅拉布拉多海海温出现下降。

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.