Mapping Neighborhood-level Emissions of Anthropogenic Air Pollutants across the Contiguous United States

Emissions of air pollutants and greenhouse gases are the main driver of many Earth system processes behind some of the grandest environmental challenges today, such as air pollution and climate change. This work introduces an unprecedented effort to map anthropogenic emissions of air pollutants at 1-km spatial resolution across the entire Contiguous United States (CONUS). This high-resolution dataset, called the Neighborhood Emission Mapping Operation (NEMO), is produced at hourly intervals based on emission inventories from the United States Environmental Protection Agency (USEPA) for the years of 2017. Fine-scale spatial allocation was achieved through distributing the emission sources using 108 spatial surrogates, factors representing the portion of a source in each 1km grid derived from survey or satellite data. Gaseous and particulate pollutants are speciated into model species for the Carbon Bond 6 chemical mechanism. All sources are grouped in 9 emission sectors and stored in the NetCDF format for air quality modeling, and in the Shapefile format for GIS users and air quality/public health managers. This dataset shows good consistency with the USEPA benchmark dataset, with a monthly difference in emissions less than 0.03% for any sector. NEMO provides the first 1 km mapping of air pollution over the CONUS, enabling new applications such as fine-scale air quality modeling, air pollution exposure assessment, and environmental justice studies. We will also discuss new developments of NEMO, including recent updates to the years of 2019 (released to the public) and 2020, rapid refresh capabilities to generate near-real-time emission datasets to support national air quality forecasting capabilities, and initial application and evaluation of NEMO in next-generation emissions and air quality models within NOAA’s Unified Forecast System.