Note that these cumulative errors are with respect to total emitted volume and are therefore impacted by errors in predicted emission event start and end times. This is why the cumulative errors for small and large emissions differ from the average quantification errors on individual events discussed earlier. In particular, estimated emission events for smaller emissions (≤ 1 kg/hr) have a slight tendency to underestimate total emission duration (see Figure for examples), which is why cumulative emissions are more underestimated in this regime. See Section S10 in the SI file for more details on cumulative quantification error.