Accession Number:

ADA169491

Title:

Field Study of Wind through and over a Forest Edge.

Descriptive Note:

Final rept. 2 Jan 84-1 Jan 86,

Corporate Author:

CONNECTICUT UNIV STORRS DEPT OF RENEWABLE NATURAL RESOURCES AND CIVIL ENGINEERING

Personal Author(s):

Report Date:

1986-04-07

Pagination or Media Count:

38.0

Abstract:

Three-dimensional miniature wind sensors that are stationary and have a high frequency response were developed and used to measure the wind structure inside and outside a forest edge. Extensive data sets were taken at different distances from the edge with the sensors arranged vertically through the canopy on movable towers both inside and outside the edge. Horizontally spaced sensors showed the flow inside the forest was correlated spatially at spacing less than 4 m. More persistent autocorrelations at higher wind speeds demonstrated that larger eddies penetrated the canopy at higher wind speeds. Measurements above the canopy demonstrated a decay of Reynolds stress with decreasing height in the roughness sublayer. Velocity spectra demonstrated that mechanical turbulence is generated by the canopy at frequencies of about 1 hz. Comparisons of in-forest profiles with the wind blowing into and out of the forest showed the effects of the edge on the turbulent intensities, streamwise and cross stream Reynolds stresses. The flow through the edge intensified the turbulences below and above the forest canopy. Conditional sampling analyses demonstrated the sweeping and ejection mechanism of large scale momentum transfer is modified by the edge. Measurements outside the edge show the evolution of intermittent stagnation eddies against the edge.

Subject Categories:

  • Forestry
  • Meteorology

Distribution Statement:

APPROVED FOR PUBLIC RELEASE