A study of the near-surface vertical distribution and chemistry of pollutants in cold-climate urban areas with the novel PACT-1D model
- 1Department of Atmospheric and Oceanic Sciences, University of California, Los Angeles, United States of America (jonaskuhn@atmos.ucla.edu)
- 2University of Alaska Fairbanks, Fairbanks, AK, United States of America
- 3Laboratory of Atmospheric Chemistry, Paul Scherrer Institute, Villingen, Switzerland
- 4LMD/IPSL, ENS, Université PSL, École Polytechnique, Institute Polytechnique de Paris, Sorbonne Université, CNRS, Paris, France
- 5Université Grenoble Alpes, CNRS, Grenoble, France
- 6University of New Hampshire, Earth Systems Research Center/EOS, Durham, New Hampshire, United States of America
- 7Department of Land, Air & Water Resources, University of California, Davis, CA, United States of America
- 8U.S. Environmental Protection Agency, Research Triangle, NC, United States of America
- 9Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX, United States of America
- 10Aerodyne Research Inc., Billerica, MA, United States of America
Cold-climate urban areas often face severe air pollution events in wintertime because of residential heating and vehicle emissions into shallow surface inversion layers. Many state-of-the-art regional chemistry-transport models cannot capture the small spatio-temporal scale of the transport and chemical processes occurring in these environments.
Here we introduce a new version of our one-dimensional atmospheric chemistry and transport model, PACT-1D that includes continuous exchange of atmospheric air with the interstitial air of a snow layer and a kinetic treatment of multi-phase chemical processes in air and snow. PACT-1D allows modeling and assessment of the interaction of transport, chemistry, and emissions on the time and length scales relevant to polluted wintertime environments.
We use the model to analyze observations made during the ALPACA campaign (Jan. and Feb. 2022 in Fairbanks, AK, USA). Many atmospheric and snow parameters were recorded, including measurements of the vertical distribution of trace species in the atmosphere and snow. The near surface transport is constrained by a passive tracer method, using reported sulfur dioxide emissions and respective profile measurements. We present preliminary model results and analyze sources of oxidants in the snow and the influence of the snow layer on the near-surface atmospheric compositions.
How to cite: Kuhn, J., Stutz, J., Cesler-Maloney, M., Simpson, W. R., Bartels-Rausch, T., Roberts, T. J., Thomas, J. L., Dibb, J., Heinlein, L., Sunday, M. O., Anastasio, C., Fahey, K., Flynn, J. H., and Guo, F.: A study of the near-surface vertical distribution and chemistry of pollutants in cold-climate urban areas with the novel PACT-1D model, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13109, https://doi.org/10.5194/egusphere-egu24-13109, 2024.
