Temporal Averaging Multiple Observations

Measurement noise can make it difficult to detect methane point sources from a single observation, but temporal averaging of multiple observations reduces the noise. We find that aggregating data from ten to twenty GHGSat-D overpasses reveals strong time-averaged plume signals from three coal mines. Once these plumes are detected, we use two methods to estimate the corresponding source rates: one based on the observed integrated mass enhancement (IME) and another based on the average cross-sectional flux.

Bulianta, China
San Juan, USA
Camden, Australia

Inferred Source Rate (kg h-1)
IME Method: 1400
X-Flux Method: 2000
Previous: n/a
Inferred Source Rate (kg h-1)
IME Method: 1150
X-Flux Method: 1500
Previous: 360-2800 (Frankenberg 2016)
Inferred Source Rate (kg h-1)
IME Method: 2200
X-Flux Method: 4000
Previous: 1000-10800 (CSIRO)

*Time-averaging and source rate quantification analytics by Varon et al. (Preliminary Results)