Estimating uncertainties in individual eddy covariance flux measurements: A comparison of methods and a proposed new method

We present a review of four methods that are currently and formerly used to estimate random flux measurement uncertainties in eddy covariance instrument systems, examining their theoretical basis. In our review, we illustrate a few of the strengths and weaknesses of each, paying particular attention to the explicit and implicit assumptions made. We then evaluate the practicality, ease of use, and relative performance for the methods reviewed. We also describe a new method of random flux uncertainty estimation that is designed to only be sensitive to random instrument noise, and compare its predictions with other methods on both real and synthetic data. We conclude that our new method is a good complement to the others examined. We also suggest that when our proposed technique is used with one or more of the other methods, new information is obtained about how contributions to the total uncertainty are distributed among their various causes. (C) 2010 Elsevier B.V. All rights reserved.