Assessment of the inverse dispersion method for the determination of methane emissions from a dairy housing

Full-Scale Investigation of Methane and Ammonia Mitigation by Early Single-Dose Slurry Storage Acidification

“…Different studies ,− have demonstrated the effect of the atmospheric stability on the accuracy of the bLS model, and the technique can only be used in conditions where the MOST can be approximately applied. Therefore, following the quality criteria defined by Flesch et al, the results from the bLS model were filtered by removing u * ≤ 0.05 m s –1 , | L | ≤ 2 m, z 0 > 0.1, σ u / u * > 4.5, and σ v / u * > 4.5 . During the whole measurement campaign, the plume from the source was caught using the downwind measurement instrument 14% of the time on the full.…”

“…Therefore, following the quality criteria defined by Flesch et al, 33 the results from the bLS model were filtered by removing u* ≤ 0.05 m s −1 , |L| ≤ 2 m, z 0 > 0.1, σ u /u* > 4.5, and σ v /u* > 4.5. 40 During the whole measurement campaign, the plume from the source was caught using the downwind measurement instrument 14% of the time on the full. After applying WD filtering criteria, 17% of the measurements with the correct WD was removed due to the quality criteria.…”

Evaluation of open and closed path sampling systems for determination of emission rates of NH3 and CH4 with inverse dispersion modelling

“…single path length between sensor and retroreflector) with a temporal resolution of 0.3 to 1 Hz. The retroreflectors used in the experiments were equipped with seven corner cubes, suitable for path lengths around 50 m. The GasFinder devices have been widely used to measure emissions from different type of agricultural sources with the IDM (Bühler et al, 2021;McGinn et al, 2019;VanderZaag et al, 2014;Harper et al, 2010;Flesch et al, 2007). The performance of the GF3 instruments is discussed in detail by .…”

“…The inverse dispersion method (IDM) based on backward Lagrangian Stochastic (bLS) dispersion modelling (e.g. Flesch et al, 2004Flesch et al, , 1995 has been widely used for the assessment of NH3 and methane (CH4) emissions from many agricultural sources: dairy housing (Bühler et al, 2021;VanderZaag et al, 2014;Harper et al, 2009), cattle feedlot (McGinn et al, 2019;Todd et al, 2011;van Haarlem et al, 2008;Flesch et al, 2007;McGinn et al, 2007), application of liquid animal manure (Kamp et al, 2021;Carozzi et al, 2013;Sintermann et al, 2011;Sanz et al, 2010), grazed pasture (McGinn et al, 2011;Voglmeier et al, 2018), rice field (Yang et al, 2019), lagoon (Ro et al, 2014;Wilson et al, 2001), composting stockpiles (Sommer et al, 2004), agricultural biodigester (Baldé et al, 2016b;Flesch et al, 2011), farm (Flesch et al, 2005) and stored liquid manure (Lemes et al, 2022;Baldé et al, 2016a;Grant et al, 2015;McGinn et al, 2008).…”

“…Concentration measurements are mostly done with an open-path optical system (e.g. Baldé et al, 2018;Bühler et al, 2021) because long path lengths (>50 m) enable a higher emission plume coverage and avoids internal surfaces (e.g. tubes, pumps) where NH3 can adsorb (Shah et al, 2006;Vaittinen et al, 2014).…”