Skip to Main content Skip to Navigation
Journal articles

NH3 spatio-temporal variability over Paris, Mexico and Toronto and its link to PM2.5 during pollution events

Abstract : Megacities can experience high levels of fine particulate matter (PM2.5) pollution linked to ammonia (NH3) mainly emitted from agricultural activities. Here, we investigate such pollution in the cities of Paris, Mexico and Toronto, each of which have distinct emission sources, agricultural regulations, and topography. Ten years of measurements from the Infrared Atmospheric Sounding Interferometer (IASI) are used to assess the spatio-temporal NH3 variability over and around the three cities. In Europe and North America, we determine that temperature is associated with the increase in NH3 atmospheric concentrations with coefficient of determination (r2) of 0.8 over agricultural areas. The variety of the NH3 sources (industry and agricultural) and the weaker temperature seasonal cycle in southern North America induce a lower correlation factor (r2 = 0.5). The three regions are subject to long range transport of NH3, as shown using HYSPLIT cluster back-trajectories. The highest NH3 concentrations measured at the city scales are associated with air masses coming from the surrounding and north-northeast regions of Paris, the south-southwest areas of Toronto, and the southeast/southwest zones of Mexico City. Using NH3 and PM2.5 measurements derived from IASI and surface observations from 2008 to 2017, annually frequent pollution events are identified in the 3 cities. Wind roses reveal statistical patterns during these pollution events with dominant northeast-southwest directions in Paris and Mexico cities, and the transboundary transport of pollutants from the United-States in Toronto. To check how well chemistry transport models perform during pollution events, we evaluate simulations made using the GEOS-Chem model for March 2011. In these simulations we find that NH3 concentrations are overall underestimated, though day-to-day variability is well represented. PM2.5 is generally underestimated over Paris and Mexico, but overestimated over Toronto.
Document type :
Journal articles
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03695678
Contributor : Catherine Cardon Connect in order to contact the contributor
Submitted on : Wednesday, June 15, 2022 - 9:37:15 AM
Last modification on : Saturday, June 25, 2022 - 3:34:09 AM

File

egusphere-2022-413.pdf
Publisher files allowed on an open archive

Licence


Distributed under a Creative Commons Attribution - NonCommercial 4.0 International License

Identifiers

Citation

Camille Viatte, Rimal Abeed, Shoma Yamanouchi, William Porter, Sarah Safieddine, et al.. NH3 spatio-temporal variability over Paris, Mexico and Toronto and its link to PM2.5 during pollution events. Atmospheric Chemistry and Physics Discussions, European Geosciences Union, 2022, pp.(Under Review). ⟨10.5194/egusphere-2022-413⟩. ⟨insu-03695678⟩

Share

Metrics

Record views

0

Files downloads

0