Abstract
The commonly measured value ofβ in the relaxed eddy accumulationmethod of about 0.56is shown to arise from the non-Gaussiannature of turbulence. Fourth-orderGram–Charlier functions forthe two-dimensional probability distributionsof variation in the horizontal component of wind velocityand concentrations of water vapour, carbondioxide and methane with respect to thevertical component of wind velocity are used to examinethe value of β.An analytical solution for β ispresented in terms of fourth-order moments.Under mean conditions, this solution givesa value for β of0.557. Variation of β is shown to be controlledprimarily by the ratio of the mean ofc'w′3 (where c'is relevant to the entity of interest andw' is vertical component of windvelocity) to the correlationcoefficient between the entity concentrationand vertical component of wind velocity.
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Milne, R., Mennim, A. & Hargreaves, K. The Value Of The β Coefficient In The Relaxed Eddy Accumulation Method In Terms Of Fourth-Order Moments. Boundary-Layer Meteorology 101, 359–373 (2001). https://doi.org/10.1023/A:1019253505890
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DOI: https://doi.org/10.1023/A:1019253505890