Estimating the Contribution of Leonard and Cross Terms to the Subfilter Scale from Atmospheric Measurements

Abstract

The theoretical analysis presented recently on the role of Leonard and cross terms in determining the subfilter contribution when using a running mean is verified using atmospheric measurements. Measurements of variables with different spectral characteristics have been used to estimate these terms usually neglected on the ground of the alleged existence of a spectral gap and the validity of the Reynolds assumption. The results obtained for artificial signals are confirmed by the analysis of the real data. The contribution is found to be important in both variances and covariances.