ABSTRACT

Over the recent decades, the increase of atmospheric carbon dioxide (CO₂) concentration has caused large effects on the earth system. However, few studies have paid attention to the effects of heterogeneity of CO₂ on the biosphere and the hydrosphere. Using a coupled diagnostic biophysical model (PML-V2) and comparing three heterogeneous CO₂ datasets (GOSAT, CMIP6 and CarbonTracker) against a baseline homogeneous data (ESRL), this study investigated the effects of heterogeneous CO₂ on gross primary production (GPP), actual evapotranspiration (ET) and water use efficiency (WUE) across the global. The results show that among the three heterogeneity CO₂, CarbonTracker produced the highest CO₂ concentration and showed the largest difference in ET (−6% to 2%), GPP (−2% to 5%) and WUE (4% to 11%) compared to those from the baseline. The most effects of the CO₂ heterogeneity occurred in summer. Russia was identified as a vulnerable region with prominent decrease in GPP and an increase in ET due to CO₂ heterogeneity. An obvious increase in GPP and a decrease in ET appeared in the Amazon rainforest, the Congo rainforest, and eastern Asia. On global scale, the effects of the CO₂ heterogeneity on ET/GPP/WUE were not significant.

摘要

近几十年来，大气中二氧化碳 (CO ₂ ) 浓度的增加对地球系统造成了巨大影响。然而，很少有研究关注CO ₂异质性对生物圈和水圈的影响。本研究使用耦合诊断生物物理模型 (PML-V2) 并将三个异质 CO ₂数据集（GOSAT、CMIP6 和 CarbonTracker）与基线均质数据 (ESRL) 进行比较，研究异质 CO ₂对总初级生产 (GPP) 的影响、全球实际蒸散量 (ET) 和用水效率 (WUE)。结果表明，在三种非均质性CO _{2 中}，CarbonTracker产生的CO ₂最高与基线相比，ET（-6% 至 2%）、GPP（-2% 至 5%）和 WUE（4% 至 11%）的差异最大。CO ₂异质性的最大影响发生在夏季。由于 CO ₂异质性，俄罗斯被确定为 GPP 显着下降和 ET 增加的脆弱地区。亚马逊热带雨林、刚果热带雨林和东亚地区出现了GPP的明显增加和ET的减少。在全球范围内，CO ₂异质性对ET/GPP/WUE 的影响不显着。