Upscaling Airborne Eddy Covariance Fluxes of Greenhouse Gases Using Landcover Information and Temporal Trends from Towers

Airborne eddy covariance is a unique tool for probing the surface-atmosphere exchange of greenhouse gases across local to landscape scales. We present on aircraft flux observations of CO₂, CH₄, H₂O, sensible heat, and latent heat collected during the Carbon Airborne Flux Experiment (CARAFE). Flights for the CARAFE campaign took place in September 2016 and May 2017 and covered a variety of ecosystems and land-use types in the Mid-Atlantic. We demonstrate that observed fluxes are able to resolve variability in surface state when combined with a 2D flux footprint analysis and high-resolution maps of landcover information. Our aircraft data show strong agreement with flux observations from towers located along the flightpaths that sample local ecosystem and land-use states, including croplands, wetland forests, and dryland forests. In addition, using a regional map of LiDAR-derived forest data, our results display an observable dependence of peak-CO₂ flux on forested biomass. We also combine flight and tower data to relate peak-CO₂ flux measurements to longer-term net CO₂ flux. These results establish the scalability of aircraft flux observations in space and time, as well as the applicability of peak flux observations to longer-term, regional dynamics of carbon.