Source-resolved variability of fine particulate matter and human exposure in an urban area
<p>Increasing the resolution of chemical transport model (CTM) predictions in urban areas is important to capture sharp spatial gradients in atmospheric pollutant concentrations and better inform air quality and emissions controls policies that protect public health. The chemical transport mod...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/22/2011/2022/acp-22-2011-2022.pdf |
| Summary: | <p>Increasing the resolution of chemical transport model (CTM) predictions in
urban areas is important to capture sharp spatial gradients in atmospheric
pollutant concentrations and better inform air quality and emissions controls
policies that protect public health. The chemical transport model PMCAMx (Particulate Matter Comprehensive Air quality Model with Extensions) was
used to assess the impact of increasing model resolution on the ability to
predict the source-resolved variability and population exposure to
<span class="inline-formula">PM<sub>2.5</sub></span> at <span class="inline-formula">36×36</span>, <span class="inline-formula">12×12</span>, <span class="inline-formula">4×4</span>, and <span class="inline-formula">1×1</span> <span class="inline-formula">km</span> resolutions over the city of Pittsburgh during typical winter
and summer periods (February and July 2017). At the coarse resolution,
county-level differences can be observed, while increasing the resolution to
<span class="inline-formula">12×12</span> <span class="inline-formula">km</span> resolves the urban–rural gradient. Increasing
resolution to <span class="inline-formula">4×4</span> <span class="inline-formula">km</span> resolves large stationary sources such as
power plants, and the <span class="inline-formula">1×1</span> <span class="inline-formula">km</span> resolution reveals intra-urban
variations and individual roadways within the simulation domain. Regional
pollutants that exhibit low spatial variability such as <span class="inline-formula">PM<sub>2.5</sub></span>
nitrate show modest changes when increasing the resolution beyond <span class="inline-formula">12×12</span> <span class="inline-formula">km</span>. Predominantly local pollutants such as elemental carbon and
primary organic aerosol have gradients that can only be resolved at the
<span class="inline-formula">1×1</span> <span class="inline-formula">km</span> scale. Contributions from some local sources are
enhanced by weighting the average contribution from each source by the
population in each grid cell. The average population-weighted <span class="inline-formula">PM<sub>2.5</sub></span>
concentration does not change significantly with resolution, suggesting that
extremely high resolution <span class="inline-formula">PM<sub>2.5</sub></span> predictions may not be necessary for
effective urban epidemiological analysis at the county level.</p> |
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| ISSN: | 1680-7316 1680-7324 |