摘要
基于CESM地球系统模式,模拟研究不同CO_(2)浓度变化情景下,在快响应阶段和平衡阶段,CO_(2)通过影响大气辐射传输过程的辐射效应和通过影响植被气孔的生理效应对气候系统的影响和作用机制异同。试验结果表明,在CO_(2)倍增的情况下,CO_(2)辐射效应和生理效应都会引起全球地表的增温。辐射效应在两个阶段的地表增温中均起主导作用,而在快响应阶段,生理效应在全球陆表增温中贡献率达到了(27.5±0.9)%。CO_(2)辐射效应和生理效应对全球水循环的影响有明显差异。在平衡阶段,CO_(2)辐射效应使全球地表蒸散增加(5.2±0.1)%,径流量增加(8.0±0.4)%;而CO_(2)生理效应使全球地表蒸散量下降(3.9±0.1)%,径流量增加(10.1±0.4)%。在快响应阶段,生理效应在蒸散量的变化中占据主导作用。在CO_(2)倍增试验基础上,又进行了大气CO_(2)浓度分别为400×10^(-6)、600×10^(-6)、800×10^(-6)、1000×10^(-6)的模拟试验。随着CO_(2)浓度的增加,受辐射效应影响,地表温度、蒸散量和降水量出现持续增加,但增幅有所放缓;受CO_(2)生理效应影响,地表蒸散量持续减少,下降幅度并未出现明显变化。CO_(2)辐射效应和生理效应的协同作用具有非线性。对于地表温度、降水和蒸散等变量,CO_(2)辐射效应和生理效应共同作用引起的变化与两者单独作用时引起的变化之和存在差异,且这种差异随着CO_(2)浓度的增加越来越显著。
The community Earth system model(CESM)was used to investigate the climate response to CO_(2) radiative forcing that is associated with CO_(2)-induced changes in atmospheric radiation,and physiological forcing that is associated with CO_(2)-induced changes in stomatal opening.The results show that both forcings cause global surface warming.During the fast adjustment processes,CO_(2)-physiological forcing contributes to(27.5±0.9)%of the total global land mean warming.The effects of the two forcings on the global water cycle are significantly different.As a result of CO_(2) doubling,at equilibrium state,the CO_(2) radiation forcing increases global surface evapotranspiration by(5.2±0.1)%and runoff by(8.0±0.4)%,CO_(2) physiological forcing decreased global surface evapotranspiration by(3.9±0.1)%and increased global runoff by(10.1±0.4)%.With the increase of CO_(2) concentration,under the influence of radiative forcing,surface temperature,evapotranspiration and precipitation continue to increase,but the increase rates slow down.Under the influence of physiological forcing,surface evapotranspiration continues to decrease,and the decreasing rate do not change significantly.The changes caused by the combined effect of two types of CO_(2) forcings are different from the sum of changes caused by the two forcings alone,and this difference becomes more and more significant with the increase of CO_(2) concentration.
作者
吴星怡
曹龙
WU Xing-Yi;CAO Long(Department of Atmospheric Sciences,School of Earth Sciences,Zhejiang University,Hangzhou 310027,China)
出处
《气候变化研究进展》
CSCD
北大核心
2024年第2期170-181,共12页
Climate Change Research
基金
国家自然科学基金项目(42275179,41975103)。