Atmospheric Pollutants Assessment during the COVID-19 Lockdown Using Remote Sensing and Ground-based Measurements in Buenos Aires, Argentina

Natacha S. Represa ； Lara S. Della Ceca ； Gabriela Abril ； María F. García Ferreyra ； Carlos M. Scavuzzo

《Aerosol and Air Quality Research》 21卷3期 (2021/03) Pp. 1-12+ap1-3-004

https://doi.org/10.4209/aaqr.2020.07.0486

摘要

The COVID-19 outbreak measures of lockdown have generated exceptional urban behavior conditions allowing the analysis of a unique scenario. We examined the atmospheric emissions in Buenos Aires, Argentina, based on urban and industrial continuous monitoring of NO_2, PM_(10) and PM_(2.5), and NO_2 (TROPOMI/Sentinel-5p) and AOD (MAIAC/MODIS, Aqua) satellite products, in addition with meteorological data. We considered the time intervals before and after the announcement of lockdown, including the same periods for 2019. The results showed that NO_2 and PM_(10) concentrations fell by ~30% and 44%, respectively, at urban stations during lockdown compared to 2019. An increase in PM at the industrial station (64% PM_(2.5) and 8% PM_(10)) could be due to the contribution of industrial sources other than vehicle traffic. Also, we observed a reduction of the tropospheric NO_2 column density mean by 54% at urban stations, and AOD values decreased between 38% and 66% during 2020. Concerning the spatial distribution, the tropospheric NO_2 column showed a significant reduction of NO_2 for the monthly mean in the metropolitan area at lockdown. Similarly, the AOD highest values had a greater extension for 2020 during the prelockdown monthly period. After the strict lockdown, concentration values increased steadily, particularly in ground-based measurements. Therefore, we were able to demonstrate the complementarity of ground-based and satellite data measurements of NO_2 and aerosol to identify the effects of lockdown measures on the spatial and temporal variability of pollutants.

關鍵字

COVID-19 ； Air quality ； Lockdown ； Remote sensing ； Ground-based monitoring