Using the Integrated Observing System for Air Quality to Improve Our Understanding of Urban NO2 Pollution in New York

Urban environments present a challenge for air quality models to simulate surface ozone and interpret satellite observations due to the modification of local meteorology or chemical properties by urban characteristics. Chemical transport models such as GEOS-CF do not properly treat such characteristics, creating questions on their influence in simulating O₃ and its precursors. In this work, we address this question through the simulation of the diurnal and vertical profiles of nitrogen dioxide (NO₂) over New York City, NY (USA) during the AEROMMA/STAQS deployment using the Weather Research and Forecasting (WRF)-driven GEOS-Chem (WRF-GC) model version 3.0. WRF-GC is run at urban scales (~4km) and includes a 2023 US EPA National Emissions Inventory (NEI) which is updated to include CRACMM v2 chemistry from Pye et al. (2024). WRF-GC includes the treatment of urban areas through the building environment parameterization (BEP) (Martilli et al., 2002), coupled with the building energy model (BEM) (Salamanca et al., 2010). Non- and urban WRF-GC results are evaluated against observations from the AEROMMA/STAQS field campaigns as well as TEMPO and TROPOMI retrievals and in situ ground monitors to test WRF-GC’s ability to reproduce the magnitude, diurnal evolution, and shape of the urban plumes. We show here the first inclusion of urban characteristics in WRF-GC and its improved ability to represent urban atmospheric chemistry in New York City in addition to insight into feasible changes that could be made to GEOS-CF without the addition of a complex urban scheme to improve performance for urban satellite retrievals.