Methane and Ethane Emission Rates, Intensities, and Trends: Aircraft Mass Balance Insights Over the Denver‐Julesburg Basin, Fall 2021

Details

• Journal Title:
  Journal of Geophysical Research: Atmospheres
• Personal Author:
  Daley, H. M. ; Dickerson, R. R. ; Stratton, P. ; He, H. ; Ren, X. ; Koss, A. R. ; Brewer, W. A. ; Baidar, S. ; Hmiel, B. ; Bon, D. ; Pierce, G. ; Weibring, P. ; Richter, D. ; Walega, J. ; Ngulat, M. C. ; Santos, A. ; Hodshire, A. L. ; Vaughn, T. L. ; Zimmerle, D. ; Fried, A.
• NOAA Program & Office:
  NESDIS (National Environmental Satellite, Data, and Information Service) ; OAR (Oceanic and Atmospheric Research) ; ARL (Air Resources Laboratory) ; CIRES (Cooperative Institute for Research in Environmental Sciences) ; CSL (Chemical Sciences Laboratory) ; NCEI (National Centers for Environmental Information)
• Description:
  Despite a 2.1-fold increase in oil and gas (O&G) production from 2012 to 2021 in the Wattenberg Field (WF) area of the Denver-Julesburg Basin (DJB), total methane (CH4) emissions have remained unchanged within measurement uncertainties (26.0 ± 6.8 t/hr in 2012, 24.0 ± 5 t/hr in 2015, and 21.4 ± 5.7 t/hr in 2021), while ethane (C2H6) emissions have decreased by a factor of 2.7 since 2015, from 7.0 ± 1.1 to 2.6 ± 0.9 t/hr in 2021. We present airborne mass flux measurements of CH4 and C2H6 quantifying total emissions, their variability, and primary sources—O&G versus concentrated animal feeding operations (CAFOs). Based on four mass balance flights in September and October 2021, total CH4 and C2H6 emissions showed significant day-to-day variability, with standard deviations of 23% and 32%, respectively. Combining in situ and LiDAR measurements with a 3-km atmospheric model improves our understanding of the reliability of flux determination. Using C2H6 and vapor-phase acetic acid (CH3COOH) as tracers, we attribute 63 ± 11% of CH4 emissions to O&G. Emission intensities (EIs), calculated as thermogenic (TG- CH4) and C2H6 emissions per barrel of oil equivalent (BOE), show a declining trend, with TG- CH4 EIs decreasing at an average annual rate of 4.4% from May 2012 to October 2021 and C2H6 EIs declining at an average annual rate of 10.8% from April 2015 to October 2021. C2H6 EIs fell at more than twice the rate of TG- CH4 EIs.
• Source:
  Journal of Geophysical Research: Atmospheres, 131(7)
• DOI:
  https://doi.org/10.1029/2025JD044370
• ISSN:
  2169-897X ; 2169-8996
• Format:
  pdf
• Publisher:
  American Geophysical Union (AGU)
• Document Type:
  Journal Article
• License:
  https://creativecommons.org/licenses/by/4.0/
• Rights Information:
  CC BY
• Compliance:
  Submitted
• Main Document Checksum:
  urn:sha-512:c6ead53e08804ef33501eeca0ecca98d7794d985540e51f6169ce54df8309e1a73cbdd905ecbf995885f1621e501da7f6d24e028d06a65c6f23db6120b9a70d4
• Download URL:
  https://repository.library.noaa.gov/view/noaa/73327/noaa_73327_DS1.pdf
• File Type:
  [PDF - 3.93 MB ]