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Vertical variability and effect of stability on turbulence characteristics down to the forest floor of a pine forest.

Launiainen, S; Vesala, T; Mölder, Meelis LU ; Mammarella, I; Smolander, S; Kolari, P; Rannik, U; Hari, P and Lindroth, Anders LU (2007) In Tellus. Series B: Chemical and Physical Meteorology 59. p.919-936
Abstract
Among the fundamental problems in canopy turbulence, particularly near the forest floor, remain the local diabatic effects and linkages between turbulent length scales and the canopy morphology. To progress on these problems, mean and higher order turbulence statistics are collected in a uniform pine forest across a wide range of atmospheric stability conditions using five 3-D anemometers in the subcanopy. The main novelties from this experiment are: (1) the agreement between second-order closure model results and measurements suggest that diabatic states in the layer above the canopy explain much of the modulations of the key velocity statistics inside the canopy except in the immediate vicinity of the trunk space and for very stable... (More)
Among the fundamental problems in canopy turbulence, particularly near the forest floor, remain the local diabatic effects and linkages between turbulent length scales and the canopy morphology. To progress on these problems, mean and higher order turbulence statistics are collected in a uniform pine forest across a wide range of atmospheric stability conditions using five 3-D anemometers in the subcanopy. The main novelties from this experiment are: (1) the agreement between second-order closure model results and measurements suggest that diabatic states in the layer above the canopy explain much of the modulations of the key velocity statistics inside the canopy except in the immediate vicinity of the trunk space and for very stable conditions. (2) The dimensionless turbulent kinetic energy in the trunk space is large due to a large longitudinal velocity variance but it is inactive and contributes little to momentum fluxes. (3) Near the floor layer, a logarithmic mean velocity profile is formed and vertical eddies are strongly suppressed modifying all power spectra. (4) A spectral peak in the vertical velocity near the ground commensurate with the trunk diameter emerged at a moderate element Reynolds number consistent with Strouhal instabilities describing wake production. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Tellus. Series B: Chemical and Physical Meteorology
volume
59
pages
919 - 936
publisher
Taylor & Francis
external identifiers
  • wos:000250752400014
  • scopus:35348944831
ISSN
0280-6509
DOI
10.1111/j.1600-0889.2007.00313.x
language
English
LU publication?
yes
id
7cdfb6b5-abbb-4489-9eb9-4d3b73c4db30 (old id 639300)
date added to LUP
2007-12-14 13:30:44
date last changed
2017-10-01 04:58:38
@article{7cdfb6b5-abbb-4489-9eb9-4d3b73c4db30,
  abstract     = {Among the fundamental problems in canopy turbulence, particularly near the forest floor, remain the local diabatic effects and linkages between turbulent length scales and the canopy morphology. To progress on these problems, mean and higher order turbulence statistics are collected in a uniform pine forest across a wide range of atmospheric stability conditions using five 3-D anemometers in the subcanopy. The main novelties from this experiment are: (1) the agreement between second-order closure model results and measurements suggest that diabatic states in the layer above the canopy explain much of the modulations of the key velocity statistics inside the canopy except in the immediate vicinity of the trunk space and for very stable conditions. (2) The dimensionless turbulent kinetic energy in the trunk space is large due to a large longitudinal velocity variance but it is inactive and contributes little to momentum fluxes. (3) Near the floor layer, a logarithmic mean velocity profile is formed and vertical eddies are strongly suppressed modifying all power spectra. (4) A spectral peak in the vertical velocity near the ground commensurate with the trunk diameter emerged at a moderate element Reynolds number consistent with Strouhal instabilities describing wake production.},
  author       = {Launiainen, S and Vesala, T and Mölder, Meelis and Mammarella, I and Smolander, S and Kolari, P and Rannik, U and Hari, P and Lindroth, Anders},
  issn         = {0280-6509},
  language     = {eng},
  pages        = {919--936},
  publisher    = {Taylor & Francis},
  series       = {Tellus. Series B: Chemical and Physical Meteorology},
  title        = {Vertical variability and effect of stability on turbulence characteristics down to the forest floor of a pine forest.},
  url          = {http://dx.doi.org/10.1111/j.1600-0889.2007.00313.x},
  volume       = {59},
  year         = {2007},
}