Wavelet analysis of coherent structures at the atmosphere-forest interface

Abstract

The two-dimensional unfolding in time and scale by the wavelet transform illustrates discrete warm and cool centers associated with organized updrafts and downdrafts, which have similar patterns but different magnitudes at different heights. Wavelet variances computed for temperature and velocity at different heights appear to have local maximum values corresponding to certain time scales, which are self-consistent and useful for objective determination of the principal time scale of the structures. Within the canopy, the principal time scales of the structures determined by this technique are 56-60 s and 40-44 s for the temperature and vertical velocity fields, respectively. -from Authors