The US EPA developed a set of modeled meteorology, emissions, air quality and pollutant deposition spanning the years 2002 through 2019. Modeled datasets cover the Conterminous US (CONUS) at a 12km horizontal grid spacing (12US1) and the Northern Hemisphere at a 108km (108NHEMI) using WRFv4.1.1 for meteorology and CMAQv5.3.2 for air quality modeling. New hemispheric and North American emissions inventories were developed using, to the extent possible, consistent input data and methods across all years, including emissions from mobile, fire, and oil and gas sources. Collectively these model outputs represent 100s of TB of data. We have selected a subset of the model input and output datasets that we hope will be most useful to the air quality research community. These datasets include: - Emissions inventory files for the CONUS for 2002-2019 suitable for input into the Sparse Matrix Operator Kernel Emissions (SMOKE) emission processor - CMAQ-ready emissions, initial conditions and boundary condition input files for the 12US1 domain for 2002-2019 - CMAQ-ready meteorology files for the 12US1 domain for 2013-2019. (Fewer years of meteorology data are included due to space constraints.) - Matched meteorology model output with surface observations for 2002-2019 - Daily average CMAQ output for the 12US1 domain for 2002-2019 for 14 pollutants - Daily average 3D CMAQ output for 44 layers for the 108NHEMI domain for 2002–2019

The US EPA developed a set of modeled meteorology, emissions, air quality and pollutant deposition spanning the years 2002 through 2019. Modeled datasets cover the Conterminous US (CONUS) at a 12km horizontal grid spacing (12US1) and the Northern Hemisphere at a 108km (108NHEMI) using WRFv4.1.1 for meteorology and CMAQv5.3.2 for air quality modeling. New hemispheric and North American emissions inventories were developed using, to the extent possible, consistent input data and methods across all years, including emissions from mobile, fire, and oil and gas sources. Collectively these model outputs represent 100s of TB of data. We have selected a subset of the model input and output datasets that we hope will be most useful to the air quality research community. These datasets include: - Emissions inventory files for the CONUS for 2002-2019 suitable for input into the Sparse Matrix Operator Kernel Emissions (SMOKE) emission processor - CMAQ-ready emissions, initial conditions and boundary condition input files for the 12US1 domain for 2002-2019 - CMAQ-ready meteorology files for the 12US1 domain for 2013-2019. (Fewer years of meteorology data are included due to space constraints.) - Matched meteorology model output with surface observations for 2002-2019 - Daily average CMAQ output for the 12US1 domain for 2002-2019 for 14 pollutants - Daily average 3D CMAQ output for 44 layers for the 108NHEMI domain for 2002–2019

This data set contains estimated hourly CO2 atmospheric mole fractions and meteorological observations over North America for the year 2010 at a horizontal grid resolution of 27 km and vertical resolution from the surface to 50 hPa. The data are output from the Penn State WRF-Chem version of the Weather Research and Forecasting (WRF) model using lateral boundary conditions and surface fluxes from the CMS-Flux Inversion system.

This dataset provides estimates of hourly carbon dioxide (CO2) emissions from the combustion of fossil fuels at 1-km resolution for the coterminous United States (CONUS) covering the years 2012 through 2017. Emissions from the ACES model are reported for ten distinct emissions source sectors: Airports and Aircraft, Commercial Buildings, Electric Power Generation facilities, Industrial point and non-point sources, Commercial Marine Vessels, Nonroad vehicles and equipment, Oil and Gas wells and facilities, Onroad vehicles, Railway engines and yards, and Residential buildings. All emissions are reported hourly on a 1-km x 1-km spatial grid. The data are provided in NetCDF version 4 format.

Files containing daily average NO, NO2, CO, and EC concentrations simulated by WRF/CMAQ at 36 km resolution for the time period 1990 – 2010. These data were contributed by EPA/ORD/CEMM/AESMD researchers to the manuscript “Four decades of United States mobile source pollutants: spatial-temporal trends assessed by ground-based monitors, air quality models, and satellites”. Portions of this dataset are inaccessible because: Data files have now been uploaded. They can be accessed through the following means: Data files have now been uploaded. Format: Data files have now been uploaded. This dataset is associated with the following publication: Henneman, L., H. Shen, C. Hogrefe, A. Russell, and C. Zigler. Four Decades of United States Mobile Source Pollutants: Spatial–Temporal Trends Assessed by Ground-Based Monitors, Air Quality Models, and Satellites. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 55(2): 882-892, (2021).

Files containing daily average NO, NO2, CO, and EC concentrations simulated by WRF/CMAQ at 36 km resolution for the time period 1990 – 2010. These data were contributed by EPA/ORD/CEMM/AESMD researchers to the manuscript “Four decades of United States mobile source pollutants: spatial-temporal trends assessed by ground-based monitors, air quality models, and satellites”. Portions of this dataset are inaccessible because: Data files have now been uploaded. They can be accessed through the following means: Data files have now been uploaded. Format: Data files have now been uploaded. This dataset is associated with the following publication: Henneman, L., H. Shen, C. Hogrefe, A. Russell, and C. Zigler. Four Decades of United States Mobile Source Pollutants: Spatial–Temporal Trends Assessed by Ground-Based Monitors, Air Quality Models, and Satellites. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 55(2): 882-892, (2021).

Gridded values of daily maximum temperature and ozone levels simulated over the continental U.S. using year-2000 and year-2030 climatic conditions as represented by two different global climate models and greenhouse gas forcing scenarios. This dataset is associated with the following publication: Fann , N., C. Nolte , P. Dolwick , T. Spero , A. CurryBrown , S. Phillips , and S. Anenberg. The Geographic Distribution and Economic Value of Climate Change-Related Ozone Health Impacts in the United States in 2030. JOURNAL OF AIR AND WASTE MANAGEMENT. Air & Waste Management Association, Pittsburgh, PA, USA, 65(5): 570-580, (2015).

These files contain gridded annual dry deposition estimates from 2002 to 2019 from the Environmental Protection Agency’s Community Multiscale Air Quality (CMAQ) model version 5.3.2 (see https://github.com/USEPA/CMAQ/tree/5.3.2) with the revised Surface Tiled Aerosol and Gaseous Exchange (STAGE) model (Appel et al., 2021) created for the EPA’s Air QUAlity TimE Series (EQUATES, https://www.epa.gov/cmaq/equates) project. These deposition fields have been downscaled from the native 12 km resolution to 300 m by mapping STAGE land use specific deposition to Moderate Resolution Imaging Spectrometer (MODIS) 17 category International Geosphere-Biosphere Programme (IGBP) classification scheme. For details on model inputs, please refer to the EPA’s EQUATES (https://www.epa.gov/cmaq/equates) project and Benish et al., 2022.

The EPA/ORD/CEMM-contributed dataset consisted of hourly CMAQ output for all model species from a 2017 simulation over the northern hemisphere along a boundary curtain of a 36 km modeling domain specified over the CONUS. The horizontal and vertical extent of the 36 km modeling domain was specified by the external collaborator and was defined by 524 boundary grid cells and 34 vertical layers. The number of output species from the 2017 hemispheric CMAQ simulation was 191 through to September 23, 2017 and 213 starting September 24, 2017. The EPA/OAR/OAQPS-contributed dataset consistent of hourly gridded CMAQ output for surface ozone concentrations from four model simulations for the year 2016. Two of these simulations were performed over the northern hemisphere at a horizontal resolution of 108 km and the other two simulations were performed over the CONUS at a horizontal resolution of 12 km. This dataset is not publicly accessible because: The size of the data provided to the external researchers (>1TB) exceeds ScienceHub limits. It can be accessed through the following means: Data can be requested by contacting hogrefe.christian@epa.gov (EPA/ORD/CEMM-contributed dataset) and henderson.barron@epa.gov (EPA/OAR/OAQPS-contributed dataset) and providing an external hard to which the data can then be copied by staff at the National Computing Center. The model simulations are stored on the /asm archival system accessible through the atmos high-performance computing (HPC) system. Due to data management policies, files on /asm are subject to expiry depending on the template of the project. Files not requested for extension after the expiry date are deleted permanently from the system. Location of EPA/ORD/CEMM-provided CMAQ model output data on asm: • /asm/grc/NRT_WRF_CMAQ/model_outputs/nhemi108/cctm.conc • /asm/MOD3EVAL/css/NRT/data/gatech/bc • /asm/MOD3EVAL/css/NRT/data/gatech/scripts • /asm/MOD3EVAL/css/NRT/data/gatech/metbdy3d Location of EPA/OAR/OAQPS-provided CMAQ model output data on asm: • /asm/ROMO/global/CMAQv5.2/2016fe_hemi_cb6_16jh/108km/output • /asm/ROMO/global/CMAQv5.2.1/2016fe_hemi_cb6_16jh/108km/ZUSA/output • /asm/ROMO/2016platform/CMAQv521/2016fe_cb6r3_ae6nvpoa_16j/12US2/output • /asm/ROMO/2016platform/CMAQv521/2016fe_zusa_cb6r3_ae6nvpoa_16j/12US2/output. Format: The CMAQ model output datasets used for the analysis presented in this manuscript and documented here were provided by scientists in EPA/ORD/CEMM and EPA/OAR/OAQPS. The EPA/ORD/CEMM-contributed dataset consisted of hourly CMAQ output for all model species from a 2017 simulation over the northern hemisphere along a boundary curtain of a 36 km modeling domain specified over the CONUS. The horizontal and vertical extent of the 36 km modeling domain was specified by the external collaborator and was defined by 524 boundary grid cells and 34 vertical layers. The number of output species from the 2017 hemispheric CMAQ simulation was 191 through to September 23, 2017 and 213 starting September 24, 2017. The EPA/OAR/OAQPS-contributed dataset consistent of hourly gridded CMAQ output for surface ozone concentrations from four model simulations for the year 2016. Two of these simulations were performed over the northern hemisphere at a horizontal resolution of 108 km and the other two simulations were performed over the CONUS at a horizontal resolution of 12 km. The data files with the CMAQ model output provided to the external researchers use the ioapi/netcdf format. Documentation of this format, including definitions of the geographical projection attributes contained in the file headers, are available at https://www.cmascenter.org/ioapi/documentation/all_versions/html. This dataset is associated with the following publication: Skipper, T.N., Y. Hu, M.T. Odman, B. Henderson, C. Hogrefe, R. Mathur, and A. Russell. EST Publication: Estimating US background ozone levels using data fusion. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA,

The EPA/ORD/CEMM-contributed dataset consisted of hourly CMAQ output for all model species from a 2017 simulation over the northern hemisphere along a boundary curtain of a 36 km modeling domain specified over the CONUS. The horizontal and vertical extent of the 36 km modeling domain was specified by the external collaborator and was defined by 524 boundary grid cells and 34 vertical layers. The number of output species from the 2017 hemispheric CMAQ simulation was 191 through to September 23, 2017 and 213 starting September 24, 2017. The EPA/OAR/OAQPS-contributed dataset consistent of hourly gridded CMAQ output for surface ozone concentrations from four model simulations for the year 2016. Two of these simulations were performed over the northern hemisphere at a horizontal resolution of 108 km and the other two simulations were performed over the CONUS at a horizontal resolution of 12 km. This dataset is not publicly accessible because: The size of the data provided to the external researchers (>1TB) exceeds ScienceHub limits. It can be accessed through the following means: Data can be requested by contacting hogrefe.christian@epa.gov (EPA/ORD/CEMM-contributed dataset) and henderson.barron@epa.gov (EPA/OAR/OAQPS-contributed dataset) and providing an external hard to which the data can then be copied by staff at the National Computing Center. The model simulations are stored on the /asm archival system accessible through the atmos high-performance computing (HPC) system. Due to data management policies, files on /asm are subject to expiry depending on the template of the project. Files not requested for extension after the expiry date are deleted permanently from the system. Location of EPA/ORD/CEMM-provided CMAQ model output data on asm: • /asm/grc/NRT_WRF_CMAQ/model_outputs/nhemi108/cctm.conc • /asm/MOD3EVAL/css/NRT/data/gatech/bc • /asm/MOD3EVAL/css/NRT/data/gatech/scripts • /asm/MOD3EVAL/css/NRT/data/gatech/metbdy3d Location of EPA/OAR/OAQPS-provided CMAQ model output data on asm: • /asm/ROMO/global/CMAQv5.2/2016fe_hemi_cb6_16jh/108km/output • /asm/ROMO/global/CMAQv5.2.1/2016fe_hemi_cb6_16jh/108km/ZUSA/output • /asm/ROMO/2016platform/CMAQv521/2016fe_cb6r3_ae6nvpoa_16j/12US2/output • /asm/ROMO/2016platform/CMAQv521/2016fe_zusa_cb6r3_ae6nvpoa_16j/12US2/output. Format: The CMAQ model output datasets used for the analysis presented in this manuscript and documented here were provided by scientists in EPA/ORD/CEMM and EPA/OAR/OAQPS. The EPA/ORD/CEMM-contributed dataset consisted of hourly CMAQ output for all model species from a 2017 simulation over the northern hemisphere along a boundary curtain of a 36 km modeling domain specified over the CONUS. The horizontal and vertical extent of the 36 km modeling domain was specified by the external collaborator and was defined by 524 boundary grid cells and 34 vertical layers. The number of output species from the 2017 hemispheric CMAQ simulation was 191 through to September 23, 2017 and 213 starting September 24, 2017. The EPA/OAR/OAQPS-contributed dataset consistent of hourly gridded CMAQ output for surface ozone concentrations from four model simulations for the year 2016. Two of these simulations were performed over the northern hemisphere at a horizontal resolution of 108 km and the other two simulations were performed over the CONUS at a horizontal resolution of 12 km. The data files with the CMAQ model output provided to the external researchers use the ioapi/netcdf format. Documentation of this format, including definitions of the geographical projection attributes contained in the file headers, are available at https://www.cmascenter.org/ioapi/documentation/all_versions/html. This dataset is associated with the following publication: Skipper, T.N., Y. Hu, M.T. Odman, B. Henderson, C. Hogrefe, R. Mathur, and A. Russell. EST Publication: Estimating US background ozone levels using data fusion. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA,