Sources and Estimates of Uncertainty in Fluxes from Aircraft

The complexity of airborne flux measurement has often led to incomplete consideration of the level of uncertainty in the resulting fluxes. This presentation builds on insights from existing literature through new experience from recent measurements of greenhouse-gas fluxes on Alaska's north slope. Samples of wind and gas concentrations collected from the air at eddy-correlation frequency are analyzed by three different schemes, each based on somewhat different assumptions, conceptual models, and compromises. These are the flux-fragment Method, the running-flux method, and the wavelet-analysis method. Sources of measurement uncertainty are first reviewed, then uncertainty associated with assumptions and compromises in the analysis are discussed and estimates presented.