Field Study of Wind Through and Over a Forest Edge

Field Study of Wind Through and Over a Forest Edge

Author: D. R. Miller

Publisher:

Published: 1986

Total Pages: 38

ISBN-13:

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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.


A Preliminary Field Study of Turbulent Flow Over and Inside a Forest Edge

A Preliminary Field Study of Turbulent Flow Over and Inside a Forest Edge

Author: J. D. Lin

Publisher:

Published: 1985

Total Pages: 116

ISBN-13:

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This study focused on field measurements to determine the spatial variability of the turbulence characteristics under various atmospheric and forest canopy conditions. A high-speed multi-channel data acquisition system was configured and tested. Fixed and movable observation towers have been set up in the University experimental forest in Coventry, Conn. Two wind velocity sensors, being tested and evaluated in the laboratory for their capability to measure the three-dimensional flow with high turbulence intensity that generally characterizes the flow regime in a forest canopy; are a dual triple-split hot-film probe and a tri-diagonal hot-film probe with a wind octant electronic sensor (WOES). The response of WOES tested in the low-speed wind nozzle appears to be promising and its compatibility with the tri-diagonal hot-film probe is being evaluated. A number of field measures has been conducted over and inside the forest canopy, using a vertical array of velocity sensors which includes a propeller anemometer, and x-hot wire and hot film anemometers.


Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports

Author:

Publisher:

Published: 1987

Total Pages: 1126

ISBN-13:

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Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.


Research in Progress

Research in Progress

Author: United States. Army Research Office

Publisher:

Published: 1987

Total Pages: 296

ISBN-13:

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Vols. for 1977- consist of two parts: Chemistry, biological sciences, engineering sciences, metallurgy and materials science (issued in the spring); and Physics, electronics, mathematics, geosciences (issued in the fall).


Wind and Trees

Wind and Trees

Author: M. P. Coutts

Publisher: Cambridge University Press

Published: 1995-08-24

Total Pages: 503

ISBN-13: 0521460379

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Covers wind behaviour, mechanical physiological responses of trees and forest management.


Plant Disturbance Ecology

Plant Disturbance Ecology

Author: Edward A. Johnson

Publisher: Academic Press

Published: 2020-10-21

Total Pages: 564

ISBN-13: 0128188146

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Disturbance ecology continues to be an active area of research, having undergone advances in many areas in recent years. One emerging direction is the increased coupling of physical and ecological processes, in which disturbances are increasingly traced back to mechanisms that cause the disturbances themselves, such as earth surface processes, mesoscale, and larger meteorological processes, and the ecological effects of interest are increasingly physiological. Plant Disturbance Ecology, 2nd Edition encourages movement away from the informal, conceptual approach traditionally used in defining natural disturbances and clearly presents how scientists can use a multitude of approaches in plant disturbance ecology. This edition includes nine revised chapters from the first edition, as well new, more comprehensive chapters on fire disturbance and beaver disturbance. Edited by leading experts in the field, Plant Disturbance Ecology, 2nd Edition is an essential resource for scientists interested in understanding plant disturbance and ecological processes. Advances understanding of natural disturbances by combining geophysical and ecological processes Provides a framework for collaboration between geophysical scientists and ecologists studying natural disturbances Includes fully updated research with 5 new chapters and revision of 11 chapters from the first edition