@article{440c614ed9bf42b2ad4d7d968a11dc19,
title = "Strong methane point sources contribute a disproportionate fraction of total emissions across multiple basins in the United States",
abstract = "Understanding, prioritizing, and mitigating methane (CH4) emissions requires quantifying CH4 budgets from facility scales to regional scales with the ability to differentiate between source sectors. We deployed a tiered observing system for multiple basins in the United States (San Joaquin Valley, Uinta, Denver-Julesburg, Permian, Marcellus). We quantify strong point source emissions (>10 kg CH4 h-1) using airborne imaging spectrometers, attribute them to sectors, and assess their intermittency with multiple revisits. We compare these point source emissions to total basin CH4 fluxes derived from inversion of Sentinel-5p satellite CH4 observations. Across basins, point sources make up on average 40% of the regional flux. We sampled some basins several times across multiple months and years and find a distinct bimodal structure to emission timescales: the total point source budget is split nearly in half by short-lasting and long-lasting emission events. With the increasing airborne and satellite observing capabilities planned for the near future, tiered observing systems will more fully quantify and attribute CH4 emissions from facility to regional scales, which is needed to effectively and efficiently reduce methane emissions.",
keywords = "fossil fuel, imaging spectroscopy, inversion, livestock, methane",
author = "Cusworth, {Daniel H.} and Thorpe, {Andrew K.} and Ayasse, {Alana K.} and David Stepp and Joseph Heckler and Asner, {Gregory P.} and Miller, {Charles E.} and Vineet Yadav and Chapman, {John W.} and Eastwood, {Michael L.} and Green, {Robert O.} and Benjamin Hmiel and Lyon, {David R.} and Duren, {Riley M.}",
note = "Funding Information: Funding for flight operations and/or data analysis referenced in this paper was supported by NASA{\textquoteright}s Carbon Monitoring System and Advanced Information System Technology programs as well as Rocky Mountain Institute, Environmental Defense Fund (EDF), California Air Resources Board (CARB), and the University of Arizona. Funding for Colorado overflights was provided by the Mark Martinez and Joey Irwin Memorial Public Projects Fund with the support of the Colorado Oil and Gas Conservation Commission and the Colorado Department of Public Health and Environment (CDPHE). The Carbon Mapper team also acknowledges the support of their sponsors including the High Tide Foundation, Bloomberg Philanthropies, Grantham Foundation, and other philanthropic donors. We thank colleagues at CARB, CDPHE, Colorado State University, University of Utah, EDF, and Pennsylvania Department of Environmental Protection for input on survey design and analysis for the California, Colorado, Utah, Permian, and Pennsylvania studies, respectively. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). We thank Dan Zimmerle for on-the-ground insights during the Denver-Julesburg flights. We thank Daniel Varon for conversations regarding inversion frameworks and validation. The Global Airborne Observatory (GAO) is managed by the Center for Global Discovery and Conservation Science at Arizona State University. The GAO is made possible by support from private foundations, visionary individuals, and Arizona State University. Funding Information: ACKNOWLEDGMENTS. Funding for flight operations and/or data analysis referenced in this paper was supported by NASA{\textquoteright}s Carbon Monitoring System and Advanced Information System Technology programs as well as Rocky Mountain Institute, Environmental Defense Fund (EDF), California Air Resources Board (CARB), and the University of Arizona. Funding for Colorado overflights was provided by the Mark Martinez and Joey Irwin Memorial Public Projects Fund with the support of the Colorado Oil and Gas Conservation Commission and the Colorado Department of Public Health and Environment (CDPHE). The Carbon Mapper team also acknowledges the support of their sponsors including the High Tide Foundation, Bloomberg Philanthropies, Grantham Foundation, and other philanthropic donors. We thank colleagues at CARB, CDPHE, Colorado State University, University of Utah, EDF, and Pennsylvania Department of Environmental Protection for input on survey design and analysis for the California, Colorado, Utah, Permian, and Pennsylvania studies, respectively. Portions of this work were carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration (80NM0018D0004). We thank Dan Zimmerle for on-the-ground insights during the Denver-Julesburg flights. We thank Daniel Varon for conversations regarding inversion frameworks and validation. The Global Airborne Observatory (GAO) is managed by the Center for Global Discovery and Conservation Science at Arizona State University. The GAO is made possible by support from private foundations, visionary individuals, and Arizona State University. Publisher Copyright: Copyright {\textcopyright} 2022 the Author(s). Published by PNAS.",
year = "2022",
month = sep,
day = "20",
doi = "10.1073/pnas.2202338119",
language = "English (US)",
volume = "119",
journal = "Proceedings of the National Academy of Sciences of the United States of America",
issn = "0027-8424",
publisher = "National Academy of Sciences",
number = "38",
}