Vehicular ammonia emissions: an underappreciated emission source in densely populated areas
<p>On-road ammonia (NH<span class="inline-formula"><sub>3</sub></span>) emissions play a significant role in fine particulate matter (PM<span class="inline-formula"><sub>2.5</sub></span>) formation in urban areas, posing sever...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-03-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/23/3819/2023/acp-23-3819-2023.pdf |
| Summary: | <p>On-road ammonia (NH<span class="inline-formula"><sub>3</sub></span>) emissions play a significant
role in fine particulate matter (PM<span class="inline-formula"><sub>2.5</sub></span>) formation in urban areas,
posing severe risks for human health. Limited studies have depicted the
spatial and temporal variations of on-road NH<span class="inline-formula"><sub>3</sub></span> emissions, in particular
lacking detailed quantification of their contributions within
densely populated areas. In this study, we established a comprehensive
vehicular NH<span class="inline-formula"><sub>3</sub></span> emission model and compiled a gridded on-road NH<span class="inline-formula"><sub>3</sub></span>
emission inventory with high spatial (3 km <span class="inline-formula">×</span> 3 km) and temporal
(monthly) resolution for mainland China. China's annual vehicular NH<span class="inline-formula"><sub>3</sub></span>
emissions are estimated to increase from 32.8 <span class="inline-formula">±</span> 1.7 to 87.1 <span class="inline-formula">±</span> 37.5 kt during the period of 2000–2019. Vehicular NH<span class="inline-formula"><sub>3</sub></span> emissions are
significantly concentrated in densely populated areas, where agricultural
emissions have relatively lower intensity. It is found that vehicular
NH<span class="inline-formula"><sub>3</sub></span> emissions could exceed agricultural emissions in the grids
containing 23.0 <span class="inline-formula">±</span> 2.1 % of the Chinese population in 2019
(approximately 326.6 <span class="inline-formula">±</span> 25.4 million people), and this ratio is up to
29.4 <span class="inline-formula">±</span> 3.0 % in winter. For extremely populous megacities such as
Beijing and Shanghai, vehicular NH<span class="inline-formula"><sub>3</sub></span> emissions exceed agricultural
emissions, where 69.2 <span class="inline-formula">±</span> 1.2 % and 72.0 <span class="inline-formula">±</span> 1.3 % of the population
resides, respectively. Thus, the significant role of on-road NH<span class="inline-formula"><sub>3</sub></span>
emissions in populated areas may have been underappreciated. This study gave
a better insight into the absolute value and relative importance of on-road
NH<span class="inline-formula"><sub>3</sub></span> emissions for different regions, seasons and population densities in
China; this is important in terms of the implications for air quality.</p> |
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| ISSN: | 1680-7316 1680-7324 |