Measuring Trace Gas Emission from Multi-Distributed Sources Using Vertical Radial Plume Mapping (VRPM) and Backward Lagrangian Stochastic (bLS) Techniques

• Published in: Atmosphere 2011-09, Vol.2 (3), p.553-566
• Main Authors: Ro, Kyoung S., Johnson, Melvin H., Hunt, Patrick G., Flesch, Thomas K.
• Format: Article
• Language: English
• Subjects: backward Lagrangian stochastic (bLS); Emission measurements; multi-distributed sources; open-path tunable diode laser absorption spectroscopy; vertical radial plume mapping (VRPM)
• ISSN: 2073-4433; 2073-4433
• DOI: 10.3390/atmos2030553

Two micrometeorological techniques for measuring trace gas emission rates from distributed area sources were evaluated using a variety of synthetic area sources. The vertical radial plume mapping (VRPM) and the backward Lagrangian stochastic (bLS) techniques with an open-path optical spectroscopic sensor were evaluated for relative accuracy for multiple emission-source and sensor configurations. The relative accuracy was calculated by dividing the measured emission rate by the actual emission rate; thus, a relative accuracy of 1.0 represents a perfect measure. For a single area emission source, the VRPM technique yielded a somewhat high relative accuracy of 1.38 ± 0.28. The bLS technique resulted in a relative accuracy close to unity, 0.98 ± 0.24. Relative accuracies for dual source emissions for the VRPM and bLS techniques were somewhat similar to single source emissions, 1.23 ± 0.17 and 0.94 ± 0.24, respectively. When the bLS technique was used with vertical point concentrations, the relative accuracy was unacceptably low.