21世纪气候变化情景下环北极地区植被生长季与活动积温变化

Changes in Vegetation Growing Season and Active Accumulated Temperature in Circum-Arctic Region under 21st Century Climate Change Scenario

基于部门间影响模式比较计划(ISI-MIP,Inter-Sectoral Impact Model Intercomparison Project)对CMIP5中5个气候(地球)系统模式模拟结果的降尺度数据,利用多模式集合预估了气候变化情景下21世纪环北极地区植被生长季与活动积温变化。研究发现:1)多模式集合模拟能够基本再现观测的初、终霜日及无霜期长度与>10℃积温的空间分布特征以及1979~2004年各指标变化趋势的空间分布特征,但其对气候变化年际变率的模拟能力较弱;2)至21世纪末,终霜日最多将提前60 d,初霜日将推迟20~40 d,无霜期延长幅度最高可达100 d,积温将增加1000~1200℃。其中RCP8.5情景下,各指标变幅最大,RCP2.6情景下变幅最小;3)各指标变幅呈现出较大的空间差异,亚欧大陆中西部的变幅普遍较大,随着气候变暖,>10℃积温增加幅度表现出明显的纬度地带性,南部增幅较大,北部增幅较小。

Based on Inter-Sectoral Impact Model Intercomparison Project(ISI-MIP)downscaling data of simulations generated by five climate(Earth)system models in CMIP5,in this study,the multi-model collection was used to estimate the vegetation growing season and active accumulated temperature changes in the circum-Arctic region in the 21st century under various climate change scenarios.The research results show that:1)Multi-model ensemble simulation can basically reproduce the observed spatial distribution characteristics of the initial and final frost days,length of the frost-free period,accumulated temperature of>10°C,and change trends of these indicators from 1979 to 2004.However,its ability to simulate the spatial differences and interannual variability of climate change is weak.2)By the end of the 21st century,the final frost day will advance by up to 60 days,initial frost day will be delayed by 20–40 days,frost-free period will extend up to 100 days,and accumulated temperature will vary by 1000–1200°C.Each of these indicators undergoes the greatest change under the RCP8.5 scenario,and the least change under the RCP2.6 scenario.3)The changes in the indicators have large spatial differences,with the changes in the central and western parts of the Eurasian continent being generally larger.With the warming of the climate,increases in the accumulated temperature>10°C gradually show obvious zonality in the latitudinal direction,with a greater increase in the south.