Methane emissions were modeled using two primary data sets, as summarized in Table . The base case data set is a gridded emission inventory for methane emissions based on the US Environmental Protection Agency's 2012 Greenhouse Gas Inventory (US EPA, 2023). This inventory includes emissions from agriculture, natural gas systems, petroleum systems, coal mines, landfills, waste treatment, and other sources. This inventory was deployed throughout the continental US modeling domain. For the counties included in the Eagle Ford Shale, however, the natural gas and petroleum system emissions in the base case inventory were replaced by site-specific inventories for methane emissions from >10,000 oil and gas production sites in the Eagle Ford, developed by Chen et al. ( ). These emissions were modeled as point sources with emissions geolocated at the sites of wells. All emissions were assumed to be constant, using annual average emission rates, except for stationary combustion, petroleum production, natural gas production, manure management, rice cultivation, and agricultural field burning, which were modeled as monthly averages. Figure shows mappings of the base case inventory with oil and gas emissions in Eagle Ford counties removed, the fine spatial scale modeling of the emissions in the Eagle Ford shale, and the combined inventory. Modeling scenarios Twelve scenarios were initially simulated to compare the impact of emission events to the impact of routine emissions on total column concentrations of methane.