Obtaining eddy fluxes for a non-homogeneous environment using wavelet cospectra.

摘要

Project FLOSS (Fluxes Over Snow Surfaces) was performed in an intermittently turbulent environment, which provided a dataset for analyzing different types of nonstationarity. The intermittent turbulence was often a result of mesoscale circulations, varying terrain, snow cover, cloud cover, vegetation, and stability. Wavelet analysis was used to calculate eddy fluxes, which were compared to fluxes from the eddy covariance method. Soundings and vertical flux profiles were created to analyze the vertical structure of the boundary layer. Time traces, flux contour profiles, and average flux time traces were created using both the eddy covariance and the wavelet techniques, with and without various types of smoothing. After comparison, the wavelet analysis was determined more appropriate for use in interpreting intermittent turbulence. Using a case study approach, the original and smoothed integrated wavelet cospectra were analyzed to study how the boundary layer reacted to various types of heterogeneity.