(1.7 × 10 -5 mol/m 2 to 4.4 × 10 -3 mol/m 2 ) (Table ). At a 1.33 km spatial resolution, the column concentrations, due to a 100 kg/hr event, vary by a factor of 41, from a minimum of 5.1 × 10 -5 mol/m 2 to a maximum of 2.1 × 10 -3 mol/m 2 . Similarly, an event of 1000 kg/hr leads to the variation of the column concentration from a minimum of 5.1 × 10 -4 mol/m 2 to a maximum of 2.1 × 10 -2 mol/m 2 , a factor of 41. Figure shows mappings of the spatial distributions of total column concentrations due to event emissions, for the same selected time periods shown in The column loadings due to emission events have different temporal patterns than the column loadings due to routine emissions. These different temporal patterns lead to differences in the relative intensity of the event-enhanced column concentrations and the column concentrations associated with routine emissions (ER). The value of the enhancement ratio, ER, for the time period was used as a measure of the degree to which emission events might be detected. Values of ER for the simulation period, are shown for location c in Figure . Summary data for location c are shown in Table . Data for locations a and b are shown in Table and.