Dominate time scale characteristics of the turbulence across canopy-atmosphere interface of a mixed broadleaved-Korean pine forest in Changbai Mountains

Abstract

The measurement and observation for this study were carried out at Forest Ecosystem Opened Research Station of Changbai Mountains (128°28′E and 42°24′ N, Jilin Province, P. R. China). Characteristics of Dominant time scales (DTSes) and dominant time scales contribution ratios (DCRs) across canopy-atmosphere interface and controlling factors were analyzed with multi-scale method. DTS of stream wise and lateral velocity components were larger than that of vertical velocity component. While DCR of vertical velocity component was larger than that of the stream wise and lateral velocity components. Effect of atmospheric stability on DCR and DTS was nonlinear. DTS under unstable conditions was larger than that under stable conditions; DTS and DCR were determined upon the original scales characteristics of upwind flow under strong stability. Canopy structure would influence DTS and DCR across canopy-atmosphere interface remarkably.

Keywords

Canopy-atmosphere interface / Multi-scale / Atmospheric stability / Dominate time scale / S718.51 / A