资源环境科技发展态势分析平台

Ozone-vegetation feedback is essential to tropospheric ozone (O-3) concentrations. The O-3 stomatal uptake damages leaf photosynthesis and stomatal conductance and, in turn, influences O-3 dry deposition. Further, O-3 directly influences isoprene emissions, an important precursor of O-3. The effects of O-3 on vegetation further alter local meteorological fields and indirectly influence O-3 concentrations. In this study, we apply a fully coupled chemistry-carbon-climate global model (ModelE2-YIBs) to evaluate changes in O-3 concentrations caused by O-3-vegetation interactions. Different parameterizations and sensitivities of the effect of O-3 damage on photosynthesis, stomatal conductance, and isoprene emissions (IPE) are implemented in the model. The results show that O-3-induced inhibition of stomatal conductance increases surface O-3 on average by +2.1 ppbv (+1.2 ppbv) in eastern China, +1.8 ppbv (-0.3 ppbv) in the eastern US, and +1.3 ppbv (+1.0 ppbv) in western Europe at high (low) damage sensitivity. Such positive feedback is dominated by reduced O-3 dry deposition in addition to the increased temperature and decreased relative humidity from weakened transpiration. Including the effect of O-3 damage on IPE slightly reduces surface O-3 concentrations by influencing precursors. However, the reduced IPE weaken surface shortwave radiative forcing of secondary organic aerosols, leading to increased temperature and O-3 concentrations in the eastern US. This study highlights the importance of interactions between O-3 and vegetation with regard to O-3 concentrations and the resultant air quality.