Millet, Dylan: University of Minnesota (Project Lead)
Baker, John: USDA-ARS (Co-Investigator)
Conley, Stephen: University of California Davis (Co-Investigator)
Griffis, Timothy (Tim): University of Minnesota (Co-Investigator)
Henze, Daven: University of Colorado (Co-Investigator)
Kolka, Randy: USFS Northern Research Station (Co-Investigator)
Wells, Kelley: University of Minnesota (Co-Investigator)
Wood, Jeffrey (Jeff): University of Missouri (Co-Investigator)
Kort, Eric: University of Michigan (Collaborator)
Cao, Hansen: University of Colorado (Post-Doc)
Deventer, Julian: University of Minnesota (Post-Doc)
LI, Xiang: University of Minnesota (Post-Doc)
Singh, Ashish: University of Minnesota (Post-Doc)
Yu, Xueying: University of Minnesota (Student-Graduate)
Project Funding:
2017 - 2020
NRA: 2016 NASA: Interdisciplinary Research in Earth Science
Funded by NASA
Abstract:
The NASA GEM (Greenhouse Emissions in the Midwest) project aims to advance scientific understanding and predictability of methane emissions from the US Corn Belt and Upper Midwest. This region is critical to the methane budget as one of the most intensively managed landscapes in the world and a global hotspot for crop and animal agriculture. It also includes some of the most wetland-rich areas in the coterminous US, along with major urban and anthropogenic emissions.
Several fundamental issues prevent accurate quantification of methane sources from this region, and compromise projections of how those sources may change: (1) Wetlands are the largest source of methane globally, but current global models lack a realistic process-based treatment of these emissions and fail to capture their spatial extent. (2) Rivers and streams have demonstrated elevated methane emissions in agricultural regions, but this process has not been quantified or integrated into bottom-up inventories. (3) Bottom-up inventories of animal methane fluxes are uncertain due to sparse measurements and lack of information on the magnitude and variability of different sources. (4) The relative importance of wetlands, agriculture, and other anthropogenic sources to the overall methane budget is thus poorly known, posing a barrier to any mitigation planning.
This presentation will provide an overview of research currently underway as part of the GEM project, including:
A) Analysis of long-term wetland methane flux measurements to better quantify the underlying drivers of emissions.
B) New observations of river and stream methane fluxes to understand their role in the overall methane budget.
C) New bottom-up agricultural measurements to constrain the methane source from representative facility types for dairy and beef cattle farms.
D) Multi-season aircraft measurements to quantify methane fluxes from key emitting facilities around the Upper Midwest.
E) Regional inverse modeling to interpret tall tower observations and the above aircraft measurements in terms of their constraints on the regional importance of agricultural and natural methane sources.
Publications:
Chen, Z., Griffis, T. J., Baker, J. M., Millet, D. B., Wood, J. D., Dlugokencky, E. J., Andrews, A. E., Sweeney, C., Hu, C., Kolka, R. K. 2018. Source Partitioning of Methane Emissions and its Seasonality in the U.S. Midwest. Journal of Geophysical Research: Biogeosciences. 123(2), 646-659. DOI: 10.1002/2017JG004356
Deventer, M. J., Griffis, T. J., Roman, D. T., Kolka, R. K., Wood, J. D., Erickson, M., Baker, J. M., Millet, D. B. 2019. Error characterization of methane fluxes and budgets derived from a long-term comparison of open- and closed-path eddy covariance systems. Agricultural and Forest Meteorology. 278, 107638. DOI: 10.1016/j.agrformet.2019.107638
More details may be found in the following project profile(s):