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Turbulence characteristics and dispersion in a forest - tests of Thomson's random-flight model

Mölder, Meelis LU ; Klemedtsson, L and Lindroth, Anders LU (2004) Flux and Concentration Footprints In Flux and Concentration Footprints (Agricultural and Forest Meteorology) 127(3-4). p.203-222
Abstract
A dispersion experiment, where the tracer SF6 Was released from line sources, was carried out within a young pine forest. Line sources made of silicone tubes were installed at different heights and distances from a tower. Vertical concentration profiles were measured on the tower and the samples were analysed with a gas chromatograph. The measured concentration profiles were compared to those calculated using Thomson's random-flight model. To provide input information to the model on turbulence, the turbulence characteristics were measured at four different heights with sonic anemometers. Data are presented for standard deviations of the velocity components, the momentum flux, the Lagrangian time scale and the mean horizontal wind... (More)
A dispersion experiment, where the tracer SF6 Was released from line sources, was carried out within a young pine forest. Line sources made of silicone tubes were installed at different heights and distances from a tower. Vertical concentration profiles were measured on the tower and the samples were analysed with a gas chromatograph. The measured concentration profiles were compared to those calculated using Thomson's random-flight model. To provide input information to the model on turbulence, the turbulence characteristics were measured at four different heights with sonic anemometers. Data are presented for standard deviations of the velocity components, the momentum flux, the Lagrangian time scale and the mean horizontal wind velocity, depending on height and thermal stability. The derived turbulence characteristics resemble previous results in the literature; but are still stand specific. Satisfactory agreement was obtained between the measured and simulated SF6 concentration profiles. However, the model clearly underestimates the concentrations in the upper part of the stand. The results should add more confidence to the continued use of Thomson's model and are useful for planning better dispersion experiments. (C) 2004 Elsevier B.V. All rights reserved. (Less)
Please use this url to cite or link to this publication:
author
organization
publishing date
type
Chapter in Book/Report/Conference proceeding
publication status
published
subject
keywords
line source, footprint, velocity standard deviation, pine forest, Lagrangian time scale, experiment, tracer
in
Flux and Concentration Footprints (Agricultural and Forest Meteorology)
volume
127
issue
3-4
pages
203 - 222
publisher
Elsevier
conference name
Flux and Concentration Footprints
external identifiers
  • wos:000225918300008
  • scopus:9944233158
ISSN
0168-1923
DOI
10.1016/j.agrformet.2004.07.014
language
English
LU publication?
yes
id
84e382e7-e3e6-45a7-b882-73ae0affecdb (old id 259064)
date added to LUP
2007-10-28 15:22:09
date last changed
2017-10-29 04:25:00
@inproceedings{84e382e7-e3e6-45a7-b882-73ae0affecdb,
  abstract     = {A dispersion experiment, where the tracer SF6 Was released from line sources, was carried out within a young pine forest. Line sources made of silicone tubes were installed at different heights and distances from a tower. Vertical concentration profiles were measured on the tower and the samples were analysed with a gas chromatograph. The measured concentration profiles were compared to those calculated using Thomson's random-flight model. To provide input information to the model on turbulence, the turbulence characteristics were measured at four different heights with sonic anemometers. Data are presented for standard deviations of the velocity components, the momentum flux, the Lagrangian time scale and the mean horizontal wind velocity, depending on height and thermal stability. The derived turbulence characteristics resemble previous results in the literature; but are still stand specific. Satisfactory agreement was obtained between the measured and simulated SF6 concentration profiles. However, the model clearly underestimates the concentrations in the upper part of the stand. The results should add more confidence to the continued use of Thomson's model and are useful for planning better dispersion experiments. (C) 2004 Elsevier B.V. All rights reserved.},
  author       = {Mölder, Meelis and Klemedtsson, L and Lindroth, Anders},
  booktitle    = {Flux and Concentration Footprints (Agricultural and Forest Meteorology)},
  issn         = {0168-1923},
  keyword      = {line source,footprint,velocity standard deviation,pine forest,Lagrangian time scale,experiment,tracer},
  language     = {eng},
  number       = {3-4},
  pages        = {203--222},
  publisher    = {Elsevier},
  title        = {Turbulence characteristics and dispersion in a forest - tests of Thomson's random-flight model},
  url          = {http://dx.doi.org/10.1016/j.agrformet.2004.07.014},
  volume       = {127},
  year         = {2004},
}