title: Micrometeorological measurements of methane and carbon dioxide fluxes at a municipal landfill.
abstract: Continuous and area-integrating monitoring of methane (CH4) and carbon dioxide (CO2) emissions was performed for 6 and 9 months, respectively, at a municipal landfill in Finland with the micrometeorological eddy covariance (EC) method. The mean CH4 emission from June to December was 0.53 mg m(-2) s(-1), while the CO2 emission between February and December averaged 1.78 mg m(-2) s(-1). The CH4 emissions from the summit area of the landfill, where active waste deposition was going on, were 1.7 times as high as from the slope area with a better surface cover. The variation in emissions over the source area of the measurement was high. Significant seasonal variation, linked to air and soil temperature, was only seen in the CO2 release rates. Results obtained with the EC method were comparable to those measured with closed static chambers. According to the EC measurements, the gas recovery system decreased CH4 fluxes by 69-79%. The ratio of the measured CH4 and CO2 emissions roughly indicated the route of the landfill gas emission, resembling the ratio of the gases measured in the gas wells (1.24) when the emission originated from the area with no oxidizing cover layer and being smaller when CH4 oxidation had taken place.
authors.affiliation: Climate and Global Change Research, Finnish Meteorological Institute, P.O. Box 503, FI-00101 Helsinki, Finland. annalea.lohila@fmi.fi
authors.forename: Annalea
authors.initials: A
authors.lastname: Lohila
authors.forename: Tuomas
authors.initials: T
authors.lastname: Laurila
authors.forename: Juha-Pekka
authors.initials: JP
authors.lastname: Tuovinen
authors.forename: Mika
authors.initials: M
authors.lastname: Aurela
authors.forename: Juha
authors.initials: J
authors.lastname: Hatakka
authors.forename: Tea
authors.initials: T
authors.lastname: Thum
authors.forename: Mari
authors.initials: M
authors.lastname: Pihlatie
authors.forename: Janne
authors.initials: J
authors.lastname: Rinne
authors.forename: Timo
authors.initials: T
authors.lastname: Vesala
mesh_terms: D000393:Air Pollutants / Q000737:chemistry*; D000397:Air Pollution; D002245:Carbon Dioxide / Q000737:chemistry*; D005387:Finland; D008697:Methane / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D013997:Time Factors
chemical_list: D000393:Air Pollutants; D002245:Carbon Dioxide; D008697:Methane