Location: Global Change and Photosynthesis Research
Project Number: 5012-21000-032-025-I
Project Type: Interagency Reimbursable Agreement
Start Date: Feb 21, 2024
End Date: Feb 20, 2029
Objective:
Provide highly accurate measurements of concentrations of nitrous oxide and methane from radio towers strategically located across the US Corn Belt and Rice Belt, to 1) provide data for improving models, 2) identify previous unknown “hot spots” of high emission, and 3) track progress in reducing overall emissions from the agricultural sector.
Approach:
Suitable radio towers have been identified at strategic locations across the Midwestern U.S. Tower operators have been contacted and have agreed to participate. At each location, gas sampling lines will be installed on the tower, with filtered inlets at 100 m above the ground surface. A pump will continuously pull air from that height to the control building at the base, where
there will be state of the art gas analyzers to measure N2O, CH4, CO2, and CO. Frequent calibration of the analyzers will be done automatically through a computer-controlled manifold, using a set of certified standard gas cylinders to ensure highest accuracy. All locations will use the same analyzers, same standard gases, and same sampling protocols to maintain complete compatibility. All data will be transferred via ethernet to a central location for QA/QC and subsequent processing. Participating scientists and post-doctoral research associates will use the collected data, along with regional weather data in
inverse models to estimate the spatial distribution of emissions, which will be compared with “bottom-up” (ground-based) models of emissions in a recursive process to improve those models. The spatial distribution of emissions will also be used to identify “hot spots”, and to track long-term changes in emissions over the 7 year life of the project.
