Goal
Holloway Group members integrate new chemical processes into the Environmental Protection Agency’s (EPA) Community Multiscale Air Quality Modeling System (CMAQ) in collaboration with Prof. Tim Bertram (UW–Madison Chemistry).
Objectives
- Construct a new version of Bertram and Thornton’s 2009 parameterization of N2O5, focusing on the role of phase separation and aerosol water in regulating reactive uptake of N2O5
- Incorporate this refined parameterization in CMAQ, leveraging new advances in organic aerosol treatment in the model, and compare with existing field determinations of N2O5 and ClNO2
- Assess the sensitivity of CMAQ derived morning NO2 vertical columns in St. Louis, MO and Phoenix, AZ to the model treatment of N2O5 chemistry and compare the model results with remote sensing measurements on NO2 vertical columns
Outcomes
This project is in the preliminary phases. Current outcomes include the beginnings of the literature review of current parameterizations and evaluation of CMAQ v5.2 heterogeneous chemistry by comparison with observations and laboratory studies. We estimate that that the NOx lifetime is too short in current models and that the product branching to ClNO2 is far too large.
Funding Partner:
Environmental Protection Agency (EPA)
Timeline:
2020 – Present
Tools:
Community Multiscale Air Quality Modeling System (CMAQ)
Core Team Members:
Tracey Holloway, Monica Harkey, Alicia Hoffman, Cara Scalpone, Tim Bertram