Nitrous Oxide Emissions from a Municipal Landfill

摘要

The first measurements of nitrous oxide (N_2O) emissions from a landfill by the eddy covariance method are reported.These measurements were compared to enclosure emission measurements conducted at the same site.The average emissions from the municipal landfill of the Helsinki Metropolitan Area were 2.7 mg N m~(-2) h~(-1) and 6.0 mg N m~(-2) h~(-1) measured by the eddy covariance and the enclosure methods,respectively.The Na_2O emissions from the landfill are about 1 order of magnitude higher than the highest emissions reported from Northern European agricultural soils,and 2 orders of magnitude higher than the highest emissions reported from boreal forest soils.Due to the small area of landfills as compared to other land-use classes,the total N_20 emissions from landfills are estimated to be of minor importance for the total emissions from Finland.Expressed as a greenhouse warming potential (GWP_(100)),the N_2O emissions make up about 3% of the total GWPioo emission of the landfill.The emissions measured by the two systems were generally of similar magnitude,with enclosure measurements showing a high small-scale spatial variation.