Abstract. Tropospheric O₃ damages leaves and directly inhibits photosynthesis, posing a threat to terrestrial carbon sinks. Previous investigations have mostly relied on sparse in-situ data or simulations using land surface models. This work is the first to use satellite data to quantify the effect of O₃ exposure on gross primary productivity (GPP). O₃-induced GPP reductions were estimated to vary between 0.36–9.55% across European forests along a North-South transect between 2003–2015, in line with prior estimates. No significant temporal trend could be determined over most of Europe, while Random Forest analysis (RFA) shows that soil moisture is a significant variable governing GPP reductions over the Mediterranean. Comparisons between this work and GPP reductions simulated by the Yale Interactive Biosphere (YIBs) model suggest that satellite-based estimates over the Mediterranean region may be biased by +12%, potentially because of differences in modelling stomatal sensitivity to soil moisture and prior O₃ exposure. This work has demonstrated for the first time that satellite-based datasets can be leveraged to assess the impact of O₃ on the terrestrial carbon sink, which are comparable with in-situ or model-based analyses.

中文翻译：

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卫星观测结果表明，臭氧引起的欧洲森林初级生产力的总下降

摘要。对流层O ₃损害叶片并直接抑制光合作用，对陆地的碳汇构成威胁。先前的研究主要依靠稀疏的原位数据或使用陆面模型的模拟。这项工作是首次使用卫星数据来量化O ₃暴露对总初级生产力（GPP）的影响。Ø ₃据估计，2003-2015年间，沿南北样带的欧洲森林在森林中引起的GPP降低幅度在0.36-9.55％之间。在欧洲大部分地区，没有确定明显的时间趋势，而随机森林分析（RFA）显示，土壤水分是控制地中海地区GPP下降的重要变量。这项工作与耶鲁互动生物圈（YIBs）模型模拟​​的GPP降低之间的比较表明，地中海地区基于卫星的估计值可能有+ 12％的偏差，这可能是由于气孔对土壤水分敏感性和先前O _3的建模差异所致。接触。这项工作首次证明了可以利用基于卫星的数据集来评估O ₃的影响。 在陆地碳汇上，可与原位或基于模型的分析相媲美。