THE ENERGY BUDGET AT THE EARTH'S SURFACE: AIR FLOW AND TURBULENCE CHARACTERISTICS IN A JAPANESE LARCH PLANTATION

Abstract

Mean horizontal windspeed profiles within and above a plantation of Japanese larch were obtained. A log-profile analysis of above-vegetation windspeeds yielded a wide range of values for the roughness length parameter (zo) and the zero plane displacement height (D), with these two parameters being highly correlated with each other. The computed Eulerian space scale of turbulence within the vegetation showed deeper penetration of large eddies after needle fall and during high winds. Power spectra showed that at the base of the plantation most of the variation in windspeed was associated with gusts of about 100 meters wavelength. Power spectra at the most dense portion of the plantation canopy showed considerable modification due to the tree spacing.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1967
Accession Number
AD0662720

Entities

People

  • L. H. Allen Jr.

Organizations

  • Agricultural Research Service

Tags

Communities of Interest

  • Advanced Electronics
  • Air Platforms
  • Energy and Power Technologies
  • Sensors

DTIC Thesaurus Topics

  • Abstracts
  • Air Flow
  • Atmospheric Motion
  • Atmospheric Sciences
  • Classification
  • Computer Programs
  • Computer Science
  • Computers
  • Contracts
  • Engineering
  • New York
  • Power Spectra
  • Security
  • United States
  • Universities
  • Wind
  • Wind Direction

Fields of Study

  • Environmental science

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Urban Planning and Geography.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster