title: Short-term landfill methane emissions dependency on wind.
abstract: Short-term (2-10h) variations of whole-landfill methane emissions have been observed in recent field studies using the tracer dilution method for emissions measurement. To investigate the cause of these variations, the tracer dilution method is applied using 1-min emissions measurements at Sandtown Landfill (Delaware, USA) for a 2-h measurement period. An atmospheric dispersion model is developed for this field test site, which is the first application of such modeling to evaluate atmospheric effects on gas plume transport from landfills. The model is used to examine three possible causes of observed temporal emissions variability: temporal variability of surface wind speed affecting whole landfill emissions, spatial variability of emissions due to local wind speed variations, and misaligned tracer gas release and methane emissions locations. At this site, atmospheric modeling indicates that variation in tracer dilution method emissions measurements may be caused by whole-landfill emissions variation with wind speed. Field data collected over the time period of the atmospheric model simulations corroborate this result: methane emissions are correlated with wind speed on the landfill surface with R(2)=0.51 for data 2.5m above ground, or R(2)=0.55 using data 85m above ground, with emissions increasing by up to a factor of 2 for an approximately 30% increase in wind speed. Although the atmospheric modeling and field test are conducted at a single landfill, the results suggest that wind-induced emissions may affect tracer dilution method emissions measurements at other landfills.
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, United States. Electronic address: delkash@udel.edu.
authors.forename: Madjid
authors.initials: M
authors.lastname: Delkash
authors.affiliation: Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710, United States. Electronic address: zhoubowen58@gmail.com.
authors.forename: Bowen
authors.initials: B
authors.lastname: Zhou
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, United States. Electronic address: gragebhan@gmail.com.
authors.forename: Byunghyun
authors.initials: B
authors.lastname: Han
authors.affiliation: Department of Civil and Environmental Engineering, University of California, Berkeley, CA 94720-1710, United States. Electronic address: tinakc@berkeley.edu.
authors.forename: Fotini K
authors.initials: FK
authors.lastname: Chow
authors.affiliation: Picarro, Inc., 3105 Patrick Henry Dr, Santa Clara, CA 95054, United States. Electronic address: rella@picarro.com.
authors.forename: Chris W
authors.initials: CW
authors.lastname: Rella
authors.affiliation: Department of Civil and Environmental Engineering, University of Delaware, Newark, DE 19716, United States. Electronic address: imhoff@udel.edu.
authors.forename: Paul T
authors.initials: PT
authors.lastname: Imhoff
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring; D008697:Methane / Q000032:analysis*; D008956:Models, Chemical; D012037:Refuse Disposal / Q000379:methods; D064091:Waste Disposal Facilities; D014919:Wind
chemical_list: D000393:Air Pollutants; D008697:Methane
keywords: Atmospheric modeling; Landfill; Methane emissions; Tracer dilution method; Wind-dependent emissions