Identification of non-turbulent motions for enhanced estimation of turbulent transport using the anisotropy of atmospheric Turbulence

Anisotropy, derived from the Reynolds stress tensor, is closely related to
turbulent energy and transport, and can be quantified using two
parameters: xB and yB. Scale-dependent properties of anisotropy
from diverse observational experiments are investigated with the help of
the Hilbert-Huang transform method. The mean yB-xB trajectories in the
barycentric map are visualized as curve clusters under different
stratification conditions. Specifically, xB increases from 0.4 to 0.9 with
the increasing scale of motions, while yB initially rises from 0.5 to 0.7
before decreasing to 0. Trajectories deviating from this pattern in
individual cases help distinguish non-turbulent motions and reconstruct
turbulence data. This analysis reveals approximately 30% to 80%
overestimation of turbulent fluxes. Therefore, anisotropy demonstrates
potential for quantifying turbulent transport in the atmospheric boundary
layer.