Herman, Daniel I.Weerasekara, ChinthakaHutcherson, Lindsay C.Giorgetta, Fabrizio R.Cossel, Kevin C.Waxman, Eleanor M.Colacion, Gabriel M.Newbury, Nathan R.Welch, Stephen M.DePaola, Brett D.Coddington, IanSantos, Eduardo A.Washburn, Brian R.2023-12-072023-12-072021-03-31https://hdl.handle.net/2097/44099Advances in spectroscopy have the potential to improve our understanding of agricultural processes and associated trace gas emissions. We implement field-deployed, open-path dual-comb spectroscopy (DCS) for precise multispecies emissions estimation from livestock. With broad atmospheric dual-comb spectra, we interrogate upwind and downwind paths from pens containing approximately 300 head of cattle, providing time-resolved concentration enhancements and fluxes of CH4, NH3, CO2, and H2O. The methane fluxes determined from DCS data and fluxes obtained with a colocated closed-path cavity ring-down spectroscopy gas analyzer agree to within 6%. The NH3 concentration retrievals have sensitivity of 10 parts per billion and yield corresponding NH3 fluxes with a statistical precision of 8% and low systematic uncertainty. Open-path DCS offers accurate multispecies agricultural gas flux quantification without external calibration and is easily extended to larger agricultural systems where point-sampling-based approaches are insufficient, presenting opportunities for field-scale biogeochemical studies and ecological monitoring.Creative Commons Attribution NonCommercial License 4.0Text