Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/30/2009
Publication Date: 2/11/2009
Citation: Ro, K.S., Johnson, M.H. 2009. Comparison of micrometeorological methods using open-path optical instruments for measuring methane emission from agricultural sites [abstract]. In: Proceedings of Air and Waste Management Association First International Greenhouse Gas Measurement Symposium, March 22-25, 2009, San Francisco, California.
Technical Abstract: In this study, we evaluated the accuracies of two relatively new micrometeorological methods using open-path tunable diode laser absorption spectrometers: vertical radial plume mapping method (US EPA OTM-10) and the backward Lagragian stochastic method (Wintrax®). We have evaluated the accuracy of these two methods in estimating emission rates from simulated distributed methane sources. A scanning open-path tunable diode laser was used to collect path-integrated concentrations (PICs) along different optical paths on a vertical plane downwind of controlled methane releases. These methods estimated methane emission rates under different atmospheric stability conditions using the meteorological and PIC data. The US EPA OTM-10 method was able to estimate the known methane emission rate with less than 20% error. The accuracy of the backward Lagrangian stochastic method under similar setting is under investigation at this time, and will be presented at the meeting.