在COVID-19爆发期间,北京的大气氨:度,来源和影响
Yangyang Zhang1, Xuejun Liu1, Yunting Fang2
1Beijing Key Laboratory of Farmland Soil Pollution Prevention and Remediation, College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193, China.
概括
在北京,COVID-19封锁减少了大气氨 (NH3) 度,但气象因素比排放变化更有影响. 同位素分析对于了解排放控制影响至关重要.
科学领域:
- 大气化学 大气化学
- 环境科学 环境科学
- 同位素地球化学 同位素地球化学
背景情况:
- 氨 (NH3) 是一种具有重大环境影响的关键空气污染物.
- COVID-19封锁为研究减少人为排放对空气质量影响提供了一个独特的机会.
研究的目的:
- 调查2020年COVID-19封锁期间和之后北京大气NH3的度和同位素 (δ15N) 值.
- 将这些发现与2017年封锁前的数据进行比较.
- 评估非农业来源对NH3污染的贡献以及排放控制的有效性.
主要方法:
- 在北京各个地点测量NH3度和δ15N值.
- 2020年的数据 (封锁和封锁后) 与2017年的数据进行比较.
- 基于同位素的来源分配,以确定NH3来源 (非农业来源,如化石燃料和城市废物).
主要成果:
- 与2017年相比,在2020年观察到更高的NH3度和更低的δ15N-NH3.
- 封锁后NH3度没有显著增加,但δ15N-NH3增加,表明来源或条件发生了变化.
- 非农业来源主导了NH3贡献 (2020年在公路上占81%,非公路62%).
- 非农业来源的贡献在非道路站点的封锁后略有增加.
结论:
- 不利的气象条件 (下边界层高度,区域交通变化) 在时间NH3变化中比减少的排放更为重要.
- 基于同位素的来源分配比单独的度变化更有效地证明了减排对大气NH3的影响.
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