COVID-AQS 2020 Emissions

Fuel-Based Inventory for Vehicle Emissions

The Fuel-Based Inventory for Vehicle Emissions (FIVE) provided here is described in Harkins et al. (2021). Additional information about FIVE can also be found in previous studies, which are cited in the ReadMe file.

The emission files are provided in netCDF format and cover the months of January to December of 2020 for both a business-as-usual (2020-BAU) and COVID-19 perturbed emissions case (2020-COVID). Additionally, we also provide 2018 and 2019 monthly emission files. Monthly emissions are separated by on-road and off-road sector emissions, as well as by fuel type, and each month has separate files covering weekdays, Saturdays, and Sundays. The data for a given day of week is split into two files, each containing 12-hours of data where times are in UTC. The emissions data within the files are reported in metric tons/hr, except for with individual VOC species, which are provided in moles/hr. The horizontal spatial resolution is approximately 4 km x 4 km and projected on the standard NEI continental US model grid. Additional information is provided in the ReadMe file.

For more information or questions, contact Brian McDonald.

Harkins, C., B. C. McDonald, D. K. Henze, and C. Wiedinmyer, A fuel-based method for updating mobile source emissions during the COVID-19 pandemic, Environmental Research Letters, doi:10.1088/1748-9326/ac0660, 2021.

Near-Real-Time (NRT) Adjusted Area and Point Source Emissions

Near-real-time (NRT) adjusted emissions for the continental U.S. are provided here for several different categories of emissions. Area and point source emissions here are adjusted from the 2017 National Emissions Inventory (NEI2017) with NRT scalings and Volatile Chemical Product (VCP) emissions are also included (McDonald et al., 2018). Oil and gas emissions here are a combination of emissions from the Fuel-based Oil and Gas Inventory (FOG, Francoeur et al., 2021) and adjusted emissions from the NEI2017. Emissions are provided for January 2019 to August 2021. International emissions from the CAMS inventory are also provided (Granier et al., 2019) and are not adjusted with NRT scalings. Emissions are separated by category and time period, with each having separate files for weekdays, Saturdays and Sundays. The data for a given day of week is split into two files, each containing 12-hours of data where times are in UTC. The emissions data within the files are reported in metric tons/hr, except for with individual VOC species, which are provided in moles/hr. For all emissions other than point sources, emissions are projected on the standard NEI continental U.S. model grid with a horizontal spatial resolution of approximately 4 km x 4 km. Point source emissions are provided with lat/lon coordinates and associated stack information for each point. Additional information is provided in the ReadMe file.

WRF-Chem/DART source code for TEMPO NO2 OSSE study

The WRF-Chem/DART, a state-of-the-art regional ensemble chemical weather forecast/data assimilation system, is used to conduct an Observing System Simulation Experiment (OSSE). This study aims at exploring the capability of geostationary satellite NO2 observation from TEMPO on NOx emissions inverse modeling. Please contact Dr. A. P. Mizzi for the latest version of codes and more instructions on how to use the WRF-Chem/DART.

Reference: Hsu, C. H., D. K. Henze, A. P. Mizzi, G. González Abad, J. He, C. Harkins, et al., An Observing System Simulation Experiment analysis of how well geostationary satellite trace-gas observations constrain NOx emissions in the US, Journal of Geophysical Research: Atmospheres, accepted, 2023.