The CR-AVE website will be undergoing a major upgrade beginning Friday, October 11th at 5:00 PM PDT. The new upgraded site will be available no later than Monday, October 21st. Please plan to complete any critical activities before or after this time.

 

Disclaimer: This material is being kept online for historical purposes. Though accurate at the time of publication, it is no longer being updated. The page may contain broken links or outdated information, and parts may not function in current web browsers. Visit https://espo.nasa.gov for information about our current projects.

 

Aircraft-based inversions quantify the importance of wetlands and livestock for...

Yu, X., D. Millet, K. C. Wells, D. K. Henze, H. Cao, T. J. Griffis, E. Kort, G. Plant, M. J. Deventer, R. K. Kolka, D. T. Roman, K. J. Davis, A. R. Desai, B. C. Baier, K. McKain, A. C. Czarnetzki, and A. Bloom (2021), Aircraft-based inversions quantify the importance of wetlands and livestock for Upper Midwest methane emissions, Atmos. Chem. Phys., 21, 951-971, doi:10.5194/acp-21-951-2021.
Abstract: 

We apply airborne measurements across three seasons (summer, winter and spring 2017–2018) in a multiinversion framework to quantify methane emissions from the US Corn Belt and Upper Midwest, a key agricultural and wetland source region. Combing our seasonal results with prior fall values we find that wetlands are the largest regional methane source (32 %, 20 [16–23] Gg/d), while livestock (enteric/manure; 25 %, 15 [14–17] Gg/d) are the largest anthropogenic source. Natural gas/petroleum, waste/landfills, and coal mines collectively make up the remainder. Optimized fluxes improve model agreement with independent datasets within and beyond the study timeframe. Inversions reveal coherent and seasonally dependent spatial errors in the WetCHARTs ensemble mean wetland emissions, with an underestimate for the Prairie Pothole region but an overestimate for Great Lakes coastal wetlands. Wetland extent and emission temperature dependence have the largest influence on prediction accuracy; better representation of coupled soil temperature–hydrology effects is therefore needed. Our optimized regional livestock emissions agree well with the Gridded EPA estimates during spring (to within 7 %) but are ∼ 25 % higher during summer and winter. Spatial analysis further shows good top-down and bottom-up agreement for beef facilities (with mainly enteric emissions) but larger (∼ 30 %) seasonal discrepancies for dairies and hog farms (with > 40 % manure emissions). Findings thus support bottom-up enteric emission estimates but suggest errors for manure; we propose that the latter reflects inadequate treatment of management factors including field application. Overall, our results confirm the importance of intensive animal agriculture for regional methane emissions, implying substantial mitigation opportunities through improved management.

PDF of Publication: 
Download from publisher's website.
Research Program: 
Interdisciplinary Science Program (IDS)
Tropospheric Composition Program (TCP)
Mission: 
ATom
ACT-America