地球系统模式FIO-ESM对北极海冰的模拟和预估

The hindcast and forecast of Arctic sea ice from FIO-ESM

评估了地球系统模式FIO-ESM(First Institute of Oceanography-Earth System Model)基于CMIP5(Coupled Model Intercomparison Project Phase 5)的历史实验对北极海冰的模拟能力,分析了该模式基于CMIP5未来情景实验在不同典型浓度路径(RCPs,Representative Concentration Pathways)下对北极海冰的预估情况。通过与卫星观测的海冰覆盖范围资料相比,该模式能够很好地模拟出多年平均海冰覆盖范围的季节变化特征,模拟的气候态月平均海冰覆盖范围均在卫星观测值±15%范围以内。FIO-ESM能够较好地模拟1979-2005年期间北极海冰的衰减趋势,模拟衰减速度为每年减少2.24×104 km2,但仍小于观测衰减速度(每年减少4.72×104 km2)。特别值得注意的是:不同于其他模式所预估的海冰一直衰减,FIO-ESM对21世纪北极海冰预估在不同情景下呈现不同的变化趋势,在RCP2.6和RCP4.5情景下,北极海冰总体呈增加趋势,在RCP6情景下,北极海冰基本维持不变,而在RCP8.5情景下,北极海冰呈现继续衰减趋势。

The hindcast and forecast of Arctic sea ice from FIO-ESM（First Institute of Oceanography-Earth System Model）based on CMIP5（Coupled Model Intercomparison Project Phase 5）historical and future climate projections experiments are evaluated and analyzed.Compared with satellite observations,the climatological Arctic sea ice extent can be well simulated by this climate model.FIO-ESM can well reproduce monthly climatological Arctic sea ice extent,within±15%of satellite observations.The decline trend of the Arctic sea ice during 1979-2005can also be simulated;however the simulated sea ice extent decreased trend is 2.24×104 km2 per year while the observed trend is 4.72×104 km2 per year.The forecast for 21st century shows that the Arctic sea ice trend will be depend on different RCPs（Representative Concentration Pathways）.Different from all other climate models,the Arctic sea ice extent will increase under RCP2.6and RCP4.5,and will have no significant trend under RCP6,while the Arctic sea ice extent will continue to decline under RCP8.5.