Mayer Monika, Schreier Stefan F, Spangl Wolfgang, Staehle Christoph, Trimmel Heidelinde, Rieder Harald E
Institute of Meteorology and Climatology, Department of Water, Atmosphere, and Environment (WAU), University of Natural Resources and Life Sciences (BOKU) Vienna Austria
Environment Agency Austria Vienna Austria.
Environ Sci Atmos. 2022 Apr 19;2(4):601-615. doi: 10.1039/d2ea00004k. eCollection 2022 Jul 14.
Despite substantial reductions in anthropogenic emissions of nitrogen oxides (NO ) and non-methane volatile organic compounds (NMVOCs) in Austria over the 30 year time period 1990-2019, summertime surface ozone (O) concentrations still exceed frequently and over wide areas the ozone maximum 8 hour mean target value for the protection of human health. We present a detailed analysis of observations of O and NO to (1) disentangle the main processes propelling O formation such as precursor emissions and meteorology and (2) quantify the impact of NO reductions and (3) estimate the effect of climate warming. The temperature sensitivity of surface O production is assessed separately for NO and VOC limited regimes. The temperature sensitivity of ozone increases with temperature in spring and summer. On average, the evaluated absolute values of the sensitivities are a factor of 2.5 larger in summer than in spring. The analysis of ambient O burdens during hot summers indicates that rising temperatures in a warming climate might largely offset the benefit of future emission reductions. MAX-DOAS formaldehyde (HCHO) measurements in Vienna from 2017 to 2019 are used as a proxy for VOC emissions. The seasonal and the temperature dependence of the observed HCHO mixing ratios indicate that biogenic VOCs (BVOCs) are the dominant source of hydrocarbons in the urban setting during the ozone season. The result agrees well with VOC emission estimates that show BVOCs to be the dominant VOC source in Austria since the early 2000s. Accordingly, anthropogenic NO emission reductions remain, outside of urban cores, the most effective instrument for policymakers to lower surface ozone concentrations in the short term.
尽管在1990 - 2019年的30年时间里，奥地利人为排放的氮氧化物（NO ）和非甲烷挥发性有机化合物（NMVOCs）大幅减少，但夏季地表臭氧（O）浓度在广大区域仍经常超过保护人类健康的臭氧8小时平均最大目标值。我们对O和NO 的观测进行了详细分析，以（1）厘清推动O形成的主要过程，如前体排放和气象因素，（2）量化NO 减排的影响，以及（3）估计气候变暖的影响。分别针对NO 和挥发性有机物（VOC）受限的情况评估了地表O生成的温度敏感性。春季和夏季，臭氧的温度敏感性随温度升高而增加。平均而言，评估的敏感性绝对值在夏季比春季大2.5倍。对炎热夏季期间的环境O负担分析表明，气候变暖导致的气温上升可能在很大程度上抵消未来减排的益处。利用2017年至2019年维也纳MAX-DOAS甲醛（HCHO）测量数据作为VOC排放的替代指标。观测到的HCHO混合比的季节和温度依赖性表明，在臭氧季节，生物源挥发性有机物（BVOCs）是城市环境中碳氢化合物的主要来源。这一结果与VOC排放估算结果非常吻合，后者表明自21世纪初以来，BVOCs一直是奥地利主要的VOC来源。因此，在城市核心区域之外，人为NO 减排仍是政策制定者短期内降低地表臭氧浓度的最有效手段。
