Continued increase in atmospheric CO 2 seasonal amplitude in the 21st century projected by the CMIP5 Earth system models
Continued increase in atmospheric CO 2 seasonal amplitude in the 21st century projected by the CMIP5 Earth system models
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DOI：
10.5194/esd-5-423-2014
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
F. Zhao;N. Zeng
中科院分区：
文献类型：
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作者：
F. Zhao;N. Zeng
抽象的。在北方半球，大气CO2浓度在春季和夏季下降，秋季和冬季上升。地面和飞机观测记录表明，这一季节性周期的幅度在过去有所增加。这种趋势在未来是否会持续下去？在本文中，我们分析了模拟的历史（1850-2005年）和未来（RCP 8.5，2006-2100年）的10个地球系统模式参与第五阶段的耦合模式相互比较项目（CMIP 5）。我们的研究结果提出了一个模型的共识，增加的CO2季节性振幅继续在整个世纪。与1961-1970年相比，2081-2090年全球平均CO2季节周期去趋势的多模式集合相对振幅增加了62 ± 19%。这一幅度的增加相当于生物圈净产量（NBP）增加68 ± 25%。结果表明，在未来CO2和温度条件下，NBP幅值的增加主要来自北方半球生长季生态系统吸收的增强。对净初级生产力（NPP）和呼吸作用的单独分析表明，增强的生态系统碳吸收贡献了约75%的幅度增加。受较高的CO2浓度和高纬度变暖的刺激，NPP的增强可能会在较高的温度下战胜呼吸作用的增加，从而导致北方生长季节的净吸收量增加。NBP变化的纬向分布和空间格局表明，45° N以北的地区是振幅增加的主要地区。模拟较强碳吸收的模型也倾向于显示NBP季节振幅的较大增加，并且模型间相关性显著（R=0.73，p
Abstract. In the Northern Hemisphere, atmospheric CO2 concentration declines in spring and summer, and rises in fall and winter. Ground-based and aircraft-based observation records indicate that the amplitude of this seasonal cycle has increased in the past. Will this trend continue in the future? In this paper, we analyzed simulations for historical (1850–2005) and future (RCP8.5, 2006–2100) periods produced by 10 Earth system models participating in the fifth phase of the Coupled Model Intercomparison Project (CMIP5). Our results present a model consensus that the increase of CO2 seasonal amplitude continues throughout the 21st century. Multi-model ensemble relative amplitude of detrended global mean CO2 seasonal cycle increases by 62 ± 19% in 2081–2090, compared to 1961–1970. This amplitude increase corresponds to a 68 ± 25% increase in net biosphere production (NBP). The results show that the increase of NBP amplitude mainly comes from enhanced ecosystem uptake during Northern Hemisphere growing season under future CO2 and temperature conditions. Separate analyses on net primary production (NPP) and respiration reveal that enhanced ecosystem carbon uptake contributes about 75% of the amplitude increase. Stimulated by higher CO2 concentration and high-latitude warming, enhanced NPP likely outcompetes increased respiration at higher temperature, resulting in a higher net uptake during the northern growing season. The zonal distribution and spatial pattern of NBP change suggest that regions north of 45° N dominate the amplitude increase. Models that simulate a stronger carbon uptake also tend to show a larger increase of NBP seasonal amplitude, and the cross-model correlation is significant (R=0.73, p