Deroubaix Adrien, Brasseur Guy, Gaubert Benjamin, Labuhn Inga, Menut Laurent, Siour Guillaume, Tuccella Paolo
Max Planck Institute for Meteorology Hamburg Germany.
Atmospheric Chemistry Observations & Modeling Laboratory (ACOM) National Center for Atmospheric Research Boulder CO USA.
Meteorol Appl. 2021 May-Jun;28(3):e1990. doi: 10.1002/met.1990. Epub 2021 May 7.
The lockdown period (March-May 2020) during the COVID-19 pandemic in Europe led to a reduction in the anthropogenic emissions of primary pollutants. For three-quarters of over 1,100 available monitoring stations, the average nitrogen dioxide (NO) concentrations decreased by at least 2.7 μg·m (or 25%) compared with the average concentrations recorded during the same period of the previous seven years. This reduction was not specific to urban or rural areas because the relative reduction was of similar magnitude in both areas. The ozone (O) response differed spatially, with positive anomalies in Northern Europe and negative anomalies in Southwestern Europe. Reduced cloudiness and related enhanced radiation in Northern Europe played a significant role in the increase of surface O concentrations by shifting the photochemical partitioning between NO and O toward more O. The level of total oxidant (O = O + NO) remained unchanged, except in Southwestern Europe where it decreased. Several episodes lasting a few days of a high level of total oxidants were observed in Northern Europe. The results illustrate the complexity of the atmospheric response to the unprecedented reduction in the emission of primary pollutants.
欧洲新冠疫情期间的封锁期（2020年3月至5月）导致主要污染物的人为排放量减少。在1100多个可用监测站中，四分之三监测站的二氧化氮（NO）平均浓度与前七年同期记录的平均浓度相比，至少下降了2.7μg·m³（或25%）。这种减少并非城市或农村地区所特有，因为两个地区的相对减少幅度相似。臭氧（O₃）的响应在空间上有所不同，北欧出现正异常，而西南欧出现负异常。北欧云量减少及相关辐射增强，通过将NO和O₃之间的光化学分配转向更多的O₃，在地表O₃浓度增加中发挥了重要作用。总氧化剂（O₃ = O₃ + NO₂）水平保持不变，但在西南欧有所下降。在北欧观察到几次持续数天的高总氧化剂水平事件。结果表明了大气对一次污染物排放前所未有的减少所做出响应的复杂性。
