edu.ucar.opensky::articles:42921 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T17:56:44.767744 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.net/ark:/85065/d7tt4w95 Urban ozone formation and sensitivities to volatile chemical products, cooking emissions, and NOx upwind of and within two Los Angeles Basin cities 2025-01-28T00:00:00Z publication https://n2t.net/ark:/85065/d7tt4w95 https://doi.org/10.5194/acp-25-1121-2025 Stockwell, C. E. author Coggon, M. M. author Schwantes, R. H. author Harkins, C. author Verreyken, B. author Lyu, C. author Zhu, Q. author Xu, L. author Gilman, J. B. author Lamplugh, A. author Peischl, J. author Robinson, M. A. author Veres, Patrick author Li, M. author Rollins, A. W. author Zuraski, K. author Baidar, S. author LIU, S. author Kuwayama, T. author Brown, S. S. author McDonald, B. C. author Warneke, C. author UCAR/NCAR - Library publisher 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 (NOx) 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 O3, NOx, 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. NOx sensitivity analyses along trajectory paths indicate that the photochemical regime of ozone varies spatially and temporally. The modeled ozone response is primarily NOx-saturated across the dense urban core and during peak ozone production in Pasadena. Lowering the inventory emissions of NOx by 25 % moves Pasadena to NOx-limited chemistry during afternoon hours and shrinks the spatial extent of NOx&nbsp;saturation towards downtown LA. Further sensitivity analyses show that using VOCs represented by a separate state inventory requires steeper NOx reductions to transition to NOx&nbsp;sensitivity, further suggesting that accurately representing VOC reactivity in inventories is critical to determining the effectiveness of future NOx&nbsp;reduction policies. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication <span style="font-family:Arial;font-size:10pt;font-style:normal;" data-sheets-root="1">Copyright author(s). This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.</span> None eng geoscientificInformation