Comparison of micrometeorological techniques in measuring gas emissions from waste lagoons

摘要

In this study, we evaluated and compared the accuracies of two micrometeorological methods using open-path tunable diode laser absorption spectrometers; vertical radial plume mapping method and the inverse dispersion model method. The accuracy of these two methods was evaluated using a 45m × 45m perforated pipe network floating on a 59 m × 68.5 m irrigation pond as a synthetic distributed emission source with known release rates of methane gas. An open-path tunable diode laser mounted on an automatic positioning device was used to collect path-integrated concentrations (PICs) along different optical paths in a vertical plane downwind of controlled methane releases. These methods estimated methane emission rates under unstable atmospheric stability conditions using meteorological and PIC data. The accuracies of these two methods under similar settings will be presented at the meeting.