Estimating the Added Value of Different Measurement Platforms toward Determining Atmospheric Ammonia Concentrations and Deposition Rates Downwind of a Feedlot

Emissions from agriculture are unregulated in the United States. Emission of reduced nitrogen species such as ammonia have continued to rise in regions with intensive agricultural activities, causing changes to regional air quality, as well as increases in reactive nitrogen deposition to vulnerable ecosystems. Concentrated Animal Feeding Operations (CAFOs) are a major source of ammonia in many regions. Because ammonia undergoes complex bidirectional fluxes, it is challenging to accurately estimate what fraction of ammonia emitted from a CAFO is sequestered in the land surface near the source, and what fraction is transported further away, where it can impact air quality, climate, and ecology. In this study, we use a turbulence-resolving atmospheric model with chemical tracer species to generate pseudo-data at a high spatial and temporal resolution; we then selectively sample the model output to simulate making measurements on different platforms. We will show results determining the added value and fundamental uncertainty associated with point measurements on stationary and mobile platforms, line-integrated or fenceline measurements, flux-gradient measurements, and other less-common measurement platforms such as aircraft or unmanned aerial vehicles.