Comparative analysis of methods for seasonal particulate organic nitrate estimation in urban areas
Abstract Accurately estimating particulate organic nitrate under high NOx and oxidizing conditions is critical. This study compared the NOx + ratio, unconstrained Positive Matrix Factorization (PMF), and Multilinear Engine-2 (ME2) methods to estimate particulate organic nitrate in Shanghai across di...
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| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-01-01
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| Series: | npj Climate and Atmospheric Science |
| Online Access: | https://doi.org/10.1038/s41612-025-00904-5 |
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| Summary: | Abstract Accurately estimating particulate organic nitrate under high NOx and oxidizing conditions is critical. This study compared the NOx + ratio, unconstrained Positive Matrix Factorization (PMF), and Multilinear Engine-2 (ME2) methods to estimate particulate organic nitrate in Shanghai across different seasons. The factors associated with organic nitrate, as identified through two receptor methods, exhibited consistent daily patterns in spring, summer, and autumn, although source contributions varied. The NOx + ratio method reported higher organic nitrate levels than the PMF and ME2 methods, likely due to the fixed RON/RAN parameter. Seasonal RON/RAN parameters were optimized based on precursor emissions in Shanghai, achieving values of 3.13 in spring, 2.25 in summer, and 1.88 in autumn. This optimization reduced discrepancies in organic nitrate using the NOx + ratio to 3.2–7.4%. The optimized parameters in this study support the rapid and accurate estimation of organic nitrate during different seasons in urban areas. |
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| ISSN: | 2397-3722 |