TY - JOUR A1 - Schneidemesser, Erika von A1 - Sibiya, Bheki A1 - Caseiro, Alexandre A1 - Butler, Tim A1 - Lawrence, Mark A1 - Leitao, Joana A1 - Lupaşcu, Aura A1 - Salvador, Pedro T1 - Learning from the COVID-19 lockdown in Berlin BT - Observations and modelling to support understanding policies to reduce NO2 JF - Atmospheric environment: X N2 - Urban air pollution is a substantial threat to human health. Traffic emissions remain a large contributor to air pollution in urban areas. The mobility restrictions put in place in response to the COVID-19 pandemic provided a large-scale real-world experiment that allows for the evaluation of changes in traffic emissions and the corresponding changes in air quality. Here we use observational data, as well as modelling, to analyse changes in nitrogen dioxide, ozone, and particulate matter resulting from the COVID-19 restrictions at the height of the lockdown period in Spring of 2020. Accounting for the influence of meteorology on air quality, we found that reduction of ca. 30-50 % in traffic counts, dominated by changes in passenger cars, corresponded to reductions in median observed nitrogen dioxide concentrations of ca. 40 % (traffic and urban background locations) and a ca. 22 % increase in ozone (urban background locations) during weekdays. Lesser reductions in nitrogen dioxide concentrations were observed at urban background stations at weekends, and no change in ozone was observed. The modelled reductions in median nitrogen dioxide at urban background locations were smaller than the observed reductions and the change was not significant. The model results showed no significant change in ozone on weekdays or weekends. The lack of a simulated weekday/weekend effect is consistent with previous work suggesting that NOx emissions from traffic could be significantly underestimated in European cities by models. These results indicate the potential for improvements in air quality due to policies for reducing traffic, along with the scale of reductions that would be needed to result in meaningful changes in air quality if a transition to sustainable mobility is to be seriously considered. They also confirm once more the highly relevant role of traffic for air quality in urban areas. KW - Urban areas KW - Air pollution KW - Emissions KW - COVID-19 KW - Nitrogen dioxide KW - Ozone KW - Europe Y1 - 2021 U6 - https://doi.org/10.1016/j.aeaoa.2021.100122 SN - 2590-1621 VL - 12 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Weger, Lindsey B. A1 - Lupaşcu, Aura A1 - Cremonese, Lorenzo A1 - Butler, Tim T1 - Modeling the impact of a potential shale gas industry in Germany and the United Kingdom on ozone with WRF-Chem JF - Elementa-sccience of the anthropocene N2 - Germany and the United Kingdom have domestic shale gas reserves which they may exploit in the future to complement their national energy strategies. However gas production releases volatile organic compounds (VOC) and nitrogen oxides (NOx), which through photochemical reaction form ground-level ozone, an air pollutant that can trigger adverse health effects e.g. on the respiratory system. This study explores the range of impacts of a potential shale gas industry in these two countries on local and regional ambient ozone. To this end, comprehensive emission scenarios are used as the basis for input to an online-coupled regional chemistry transport model (WRF-Chem). Here we simulate shale gas scenarios over summer (June, July, August) 2011, exploring the effects of varying VOC emissions, gas speciation, and concentration of NOx emissions over space and time, on ozone formation. An evaluation of the model setup is performed, which exhibited the model’s ability to predict surface meteorological and chemical variables well compared with observations, and consistent with other studies. When different shale gas scenarios were employed, the results show a peak increase in maximum daily 8-hour average ozone from 3.7 to 28.3 μg m–3. In addition, we find that shale gas emissions can force ozone exceedances at a considerable percentage of regulatory measurement stations locally (up to 21% in Germany and 35% in the United Kingdom) and in distant countries through long-range transport, and increase the cumulative health-related metric SOMO35 (maximum percent increase of ~28%) throughout the region. Findings indicate that VOC emissions are important for ozone enhancement, and to a lesser extent NOx, meaning that VOC regulation for a future European shale gas industry will be of especial importance to mitigate unfavorable health outcomes. Overall our findings demonstrate that shale gas production in Europe can worsen ozone air quality on both the local and regional scales. KW - Shale gas KW - WRF-Chem KW - European air quality KW - Ozone KW - Methane leakage KW - Emission scenarios Y1 - 2019 U6 - https://doi.org/10.1525/elementa.387 SN - 2325-1026 VL - 7 PB - Univ California Press CY - Oakland ER -