Measurement report: Airborne measurements of NOx fluxes over Los Angeles during the RECAP-CA 2021 campaign
Creators
-
1.
Max Planck Institute for Chemistry
-
2.
University of California, Berkeley
-
3.
California Institute of Technology
-
4.
Naval Postgraduate School
Abstract
Nitrogen oxides (NOx≡NO+NO₂) are involved in most atmospheric photochemistry, including the formation of tropospheric ozone (O3). While various methods exist to accurately measure NOx concentrations, it is still a challenge to quantify the source and flux of NOx emissions. We present airborne measurements of NOx and winds used to infer the emission of NOx across Los Angeles. The measurements were obtained during the research aircraft campaign RECAP-CA (Re-Evaluating the Chemistry of Air Pollutants in CAlifornia) in June 2021. Geographic allocations of the fluxes are compared to the NOx emission inventory from the California Air Resources Board (CARB). We find that the NOx fluxes have a pronounced weekend effect and are highest in the eastern part of the San Bernardino Valley. The comparison of the RECAP-CA and the modeled CARB NOx fluxes suggests that the modeled emissions are higher than expected near the coast and in Downtown Los Angeles and lower than expected further inland in the eastern part of the San Bernardino Valley.
Copyright and License
© Author(s) 2023. This work is distributed under the Creative Commons Attribution 4.0 License. Published by Copernicus Publications on behalf of the European Geosciences Union.
Acknowledgement
We acknowledge Horst Fischer and Lenard Röder for valuable discussions and proofreading this work. The wavelet software was provided by Christopher Torrence and Gilbert P. Compo and is available at http://paos.colorado.edu/research/wavelets/ (last access: 11 January 2022). Plots including Google Maps data were created with a MATLAB function by Bar-Yehuda (2022). This work has been supported by the Max Planck Graduate Center with the Johannes Gutenberg University Mainz (MPGC).
Funding
The RECAP-CA aircraft campaign has been funded by the California Air Resources Board (grant nos. 20RD003 and 20AQP012) and the South Coast Air Quality Management District (grant no. 20327).
The article processing charges for this open-access publication were covered by the Max Planck Society.
Code Availability
The codes used for the wavelet transformation and the footprint calculation are available at https://doi.org/10.5281/zenodo.8425485 (Zhu and Pfannerstill, 2023).
Data Availability
Data measured during the flight campaign, computed fluxes and footprints are available at https://doi.org/10.5281/zenodo.8199013 (Nussbaumer et al., 2023). Additional files, for example, in different resolutions, are available from the corresponding authors upon request.
Supplemental Material
The supplement related to this article is available online at: https://doi.org/10.5194/acp-23-13015-2023-supplement.
Contributions
CMN analyzed the data, with contributions from BKP, QZ, and EYP. CMN wrote the paper. BKP, EYP, PW, BCS, CA, RW, AB, JHS, AHG, and RCC participated in the field campaign. All co-authors contributed to designing the study and proofreading the paper.
Conflict of Interest
At least one of the (co-)authors is a member of the editorial board of Atmospheric Chemistry and Physics. The peer-review process was guided by an independent editor, and the authors also have no other competing interests to declare.
Additional Information
This paper was edited by Qi Chen and reviewed by Glenn Wolfe and one anonymous referee.
Files
acp-23-13015-2023.pdf
Additional details
Related works
- Is new version of
- Discussion Paper: 10.5194/egusphere-2023-601 (DOI)
- Is supplemented by
- Software: 10.5281/zenodo.8425485 (DOI)
- Dataset: 10.5281/zenodo.8199013 (DOI)
- Supplemental Material: 10.5194/acp-23-13015-2023-supplement (DOI)
Funding
- California Air Resources Board
- 20RD003
- California Air Resources Board
- 20AQP012
- California Air Resources Board
- 20327
- Max Planck Society
Dates
- Submitted
-
2023-03-29
- Accepted
-
2023-08-14
Caltech Custom Metadata
- Caltech groups
- Division of Chemistry and Chemical Engineering (CCE) , Division of Geological and Planetary Sciences (GPS)
- Publication Status
- Published