The entire year of 2016 is modeled with CMAQ version 5.2.1 (doi:10.5281/zenodo.1212601). The chosen simulation is evaluated extensively for air quality and meteorology performance. CMAQ is applied for a domain covering the CONUS using 12 km sized horizontal grid cells. The vertical atmosphere is resolved with 35 layers extending from the surface to the tropopause with finer resolution in the planetary boundary layer to better capture diurnal variation in mixing height. The Carbon Bond 6 revision 3 gas phase chemical mechanism, ISORROPIA II inorganic aerosol thermodynamics, aqueous phase cloud chemistry, and wet and dry depositional processes are included in the simulation. Primary organic aerosol is treated as non-volatile. SOA formation is described by semi-volatile partitioning of lumped gas-phase groups that include benzene, toluene, xylenes, naphthalene, monoterpenes, isoprene, and sesquiterpenes and particle-phase oligomerization. AqSOA is formed from glyoxal, glyoxal analogues (methylglyoxal and glycolaldehyde), and isoprene epoxydiols. Biogenic emissions are estimated using the Biogenic Emission Inventory System (BEIS) version 3.6.1 Anthropogenic emissions are based on the 2016 emissions modeling platform developed by the U.S. EPA. Lateral boundary inflow is extracted from a coarser scale model simulation that covered the northern hemisphere. Meteorological inputs from the Weather Research and Forecasting (WRF) model version 3.8 are used to develop biogenic emissions and drive atmospheric dynamics using the same domain and projection specifications as the CMAQ model simulation. This dataset is not publicly accessible because: This data has been previously made available to the public as part of a Federal rulemaking. It can be accessed through the following means: Docket EPA-HQ-OAR-2022-0829 “Modeling Input Files for the Air Quality and Benefits Analysis for the Light and Medium Duty Vehicle (LMDV) Multipollutant Final Rule (FRM)”. Format: The CMAQ model output files are netCDF format and include header metadata information describing all variables and variable units on the file.

This dataset is associated with the following publication: Smith, E., K. Baker, M. El-Sayed, C. Hennigan, S. Rosanka, and A. Carlton. Gas-Phase Water-Soluble Organic Carbon: CMAQ Model Evaluation in Baltimore County. ACS Earth and Space Chemistry. American Chemical Society, Washington, DC, USA, 9(6): 1501-1509, (2025).