Université libre de Bruxelles (ULB), Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Belgium.
Royal Belgian Institute for Space Aeronomy, Brussels, Belgium.
Sci Rep. 2022 Jul 19;12(1):12327. doi: 10.1038/s41598-022-15836-w.
The presence of a weekly cycle in the abundance of an atmospheric constituent is a typical fingerprint for the anthropogenic nature of its emission sources. However, while ammonia is mainly emitted as a consequence of human activities, a weekly cycle has never been detected in its abundances at large scale. We expose here for the first time the presence of a weekend effect in the NH total columns measured by the IASI satellite sounder over the main agricultural source regions in Europe: northwestern Europe (Belgium-the Netherlands-northwest Germany), the Po Valley, Brittany, and, to a lesser extent, the Ebro Valley. A decrease of 15% relative to the weekly mean is seen on Sunday-Monday observations in northwestern Europe, as a result of reduced NH emissions over the weekend. This is confirmed by in situ NH concentration data from the National Air Quality Monitoring Network in the Netherlands, where an average reduction of 10% is found around midnight on Sunday. The identified weekend effect presents a strong seasonal variability, with two peaks, one in spring and one in summer, coinciding with the two main (manure) fertilization periods. In spring, a reduction on Sunday-Monday up to 53 and 26% is found in the NH satellite columns and in situ concentrations, respectively, as fertilization largely drives atmospheric NH abundances at this time of the year.
大气成分丰度存在每周循环是其人为排放源的典型特征。然而，尽管氨主要是人类活动的结果，但在其大规模丰度中从未检测到每周循环。我们在这里首次揭示了大气总柱 NH 在欧洲主要农业源区（西北欧（比利时-荷兰-西北德国）、波河谷、布列塔尼，以及在较小程度上的埃布罗河谷）的 IASI 卫星探测中存在周末效应：在西北欧，周日至周一的观测结果显示相对每周平均值下降了 15%，这是由于周末 NH 排放减少所致。这得到了荷兰国家空气质量监测网络的现场 NH 浓度数据的证实，在那里周日午夜前后发现平均减少了 10%。所确定的周末效应具有强烈的季节性变化，有两个峰值，一个在春季，一个在夏季，这与两个主要（粪肥）施肥期相对应。在春季，NH 卫星柱和现场浓度的周日至周一的降幅分别达到 53%和 26%，因为施肥在每年的这个时候很大程度上驱动了大气 NH 的丰度。
