The ER improves at finer spatial resolution. ER for a 1000 kg/hr event averages 2.56, when the simulation is done at a 1.33 km resolution, indicating a 1000 kg event increases local column concentrations at location c by 156%, on average. ER exceeds 2 in 54.7% of the simulation hours at this finer resolution, and exceeds 3 in 24.3% of the simulation hours. In the 1300-1400 hour time period, the ER exceeds 2 in 47.0% of 1300-1400 simulation hours. Total column concentrations of methane due to nearby emission events are shown in Figure . At a 4 km spatial resolution, the averaged column concentration due to these nearby events is 1.2 × 10 -4 mol/m 2 with a maximum of up to 9.8 × 10 -4 mol/m 2 (Table ) at location c. At a 1.33 km spatial resolution, the averaged column concentration, due to nearby events, is 1.3 × 10 -4 mol/m 2 with a maximum of 1.8 × 10 -3 mol/m 2 . Figure shows mappings of the spatial distributions of total column concentrations due to these nearby event emissions for the same selected time periods shown in Figure .