Urban ozone formation and sensitivities to volatile chemical products, cooking emissions, and NO<sub><i>x</i></sub> upwind of and within two Los Angeles Basin cities
<p><span id="page1122"/>Volatile chemical products (VCPs) and other non-traditional anthropogenic sources, such as cooking, contribute substantially to the volatile organic compound (VOC) budget in urban areas, but their impact on ozone formation is less certain. This study emp...
Saved in:
| Main Authors: | , , , , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2025-01-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://acp.copernicus.org/articles/25/1121/2025/acp-25-1121-2025.pdf |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| Summary: | <p><span id="page1122"/>Volatile chemical products (VCPs) and other non-traditional anthropogenic sources, such as cooking, contribute substantially to the volatile organic compound (VOC) budget in urban areas, but their impact on ozone formation is less certain. This study employs Lagrangian box modeling and sensitivity analyses to evaluate ozone response to sector-specific VOC and nitrogen oxide (NO<span class="inline-formula"><sub><i>x</i></sub></span>) emissions in two Los Angeles (LA) Basin cities during the summer of 2021. The model simulated the photochemical processing and transport of temporally and spatially gridded emissions from the FIVE-VCP-NEI17NRT inventory and accurately simulates the variability and magnitude of O<span class="inline-formula"><sub>3</sub></span>, NO<span class="inline-formula"><sub><i>x</i></sub></span>, and speciated VOCs in Pasadena, CA. VOC sensitivity analyses show that anthropogenic VOCs (AVOC) enhance the mean daily maximum 8 h average ozone in Pasadena by 13 ppb, whereas biogenic VOCs (BVOCs) contribute 9.4 ppb. Of the ozone influenced by AVOCs, VCPs represent the largest fraction at 45 %, while cooking and fossil fuel VOCs are comparable at 26 % and 29 %, respectively. NO<span class="inline-formula"><sub><i>x</i></sub></span> sensitivity analyses along trajectory paths indicate that the photochemical regime of ozone varies spatially and temporally. The modeled ozone response is primarily NO<span class="inline-formula"><sub><i>x</i></sub></span>-saturated across the dense urban core and during peak ozone production in Pasadena. Lowering the inventory emissions of NO<span class="inline-formula"><sub><i>x</i></sub></span> by 25 % moves Pasadena to NO<span class="inline-formula"><sub><i>x</i></sub></span>-limited chemistry during afternoon hours and shrinks the spatial extent of NO<span class="inline-formula"><sub><i>x</i></sub></span> saturation towards downtown LA. Further sensitivity analyses show that using VOCs represented by a separate state inventory requires steeper NO<span class="inline-formula"><sub><i>x</i></sub></span> reductions to transition to NO<span class="inline-formula"><sub><i>x</i></sub></span> sensitivity, further suggesting that accurately representing VOC reactivity in inventories is critical to determining the effectiveness of future NO<span class="inline-formula"><sub><i>x</i></sub></span> reduction policies.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |