Methane emissions from a Californian landfill, determined from airborne remote sensing and in situ measurements
Authors
Krautwurst, Sven
Gerilowski, Konstantin
Jonsson, Haflidi H.
Thompson, David R.
Kolyer, Richard W.
Iraci, Laura T.
Thorpe, Andrew K.
Horstjann, Markus
Eastwood, Michael
Leifer, Ira
Subjects
Advisors
Date of Issue
2017/09/20
Date
20 September 2017
Publisher
Copernicus Publications
Language
Abstract
Fugitive emissions from waste disposal sites are important anthropogenic sources of the greenhouse gas methane (CH₄). As a result of the growing world population and the recognition of the need to control greenhouse gas emissions, this anthropogenic source of CH₄ has received much recent attention. However, the accurate assessment of the CH₄ emissions from landfills by modeling and existing measurement techniques is challenging. This is because of inaccurate knowledge of the model parameters and the extent of and limited accessibility to landfill sites. This results in a large uncertainty in our knowledge of the emissions of CH₄ from landfills and waste management. In this study, we present results derived from data collected during the research campaign COMEX (CO₂ and MEthane eXperiment) in late summer 2014 in the Los Angeles (LA) Basin. One objective of COMEX, which comprised aircraft observations of methane by the remote sensing Methane Airborne MAPper (MAMAP) instrument and a Picarro greenhouse gas in situ analyzer, was the quantitative investigation of CH₄ emissions. Enhanced CH₄ concentrations or “CH₄
plumes” were detected downwind of landfills by remote sensing aircraft surveys. Subsequent to each remote sensing survey, the detected plume was sampled within the atmospheric boundary layer by in situ measurements of atmospheric parameters such as wind information and dry gas mixing ratios of CH₄ and carbon dioxide (CO₂) from the same aircraft. This was undertaken to facilitate the independent estimation of the surface fluxes for the validation of the remote sensing estimates. During the COMEX campaign, four landfills in the LA Basin were surveyed. One landfill repeatedly showed a clear emission plume. This landfill, the Olinda Alpha Landfill, was investigated on 4 days during the last week of August and first days of September 2014. Emissions were estimated for all days using a mass balance approach. The derived emissions vary between 11.6 and 17.8 ktCH₄
yr ¯¹ with related uncertainties in the range of 14 to 45 %. The comparison of the remote sensing and in situ based CH₄ emission rate estimates reveals good agreement within the error bars with an average of the absolute differences of around 2.4 ktCH₄ yr ¯¹ (±2.8 ktCH₄ yr ¯¹). The US Environmental Protection Agency (EPA) reported inventory value is 11.5 ktCH₄ yr ¯¹ for 2014, on average 2.8 ktCH₄ yr ¯¹ (±1.6 ktCH₄ yr ¯¹) lower than our estimates acquired in the afternoon in late summer 2014. This difference may in part be explained by a possible leak located on the southwestern slope of the landfill, which we identified in the observations of the Airborne Visible/Infrared Imaging Spectrometer – Next Generation (AVIRIS-NG) instrument, flown contemporaneously aboard a second aircraft on 1 day.
Type
Article
Description
The article of record as published may be found at https://dx.doi.org/10.5194/amt-10-3429-2017
The Supplement related to this article is available online at https://doi.org/10.5194/amt-10-3429-2017-supplement
The Supplement related to this article is available online at https://doi.org/10.5194/amt-10-3429-2017-supplement
Series/Report No
Department
Organization
Naval Postgraduate School
Identifiers
NPS Report Number
Sponsors
NASA AMES
CIRPAS
CIRPAS
Funder
GFZ German Research Centre for Geosciences
University and State of Bremen and the Helmholtz Center Potsdam
European Space Agency (ESA)
National Aeronautics and Space Administration (NASA)
University and State of Bremen and the Helmholtz Center Potsdam
European Space Agency (ESA)
National Aeronautics and Space Administration (NASA)
Format
24 p.
Citation
Krautwurst, Sven, et al. "Methane emissions from a Californian landfill, determined from airborne remote sensing and in situ measurements." Atmospheric Measurement Techniques 10.9 (2017): 3429-3452.
Distribution Statement
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. As such, it is in the public domain, and under the provisions of Title 17, United States Code, Section 105, it may not be copyrighted.