DOI: 10.1016/j.atmosenv.2015.02.061
Scopus记录号: 2-s2.0-84923583290
论文题名: Contribution of coherent structures to momentum and concentration fluxes over a flat vegetation canopy modelled in a wind tunnel
作者: Conan B ; , Aubrun S ; , Coudour B ; , Chetehouna K ; , Garo J ; -P
刊名: Atmospheric Environment
ISSN: 0168-2563
EISSN: 1573-515X
出版年: 2015
卷: 107 起始页码: 329
结束页码: 341
语种: 英语
英文关键词: Atmospheric boundary-layer simulation
; Coherent turbulent structures
; Concentration fluctuations
; Concentration flux
; Forest canopy turbulence
; Gas dispersion
; Wind-tunnel experiment
Scopus关键词: Anemometers
; Atmospheric movements
; Atmospheric thermodynamics
; Boundary layer flow
; Boundary layers
; Deforestation
; Dispersion (waves)
; Forestry
; Gases
; Momentum
; Shear flow
; Turbulent flow
; Vegetation
; Volatile organic compounds
; Wind tunnels
; Concentration fluctuation
; Forest canopies
; Gas dispersion
; Turbulent structures
; Wind tunnel experiment
; Atmospheric boundary layer
; volatile organic compound
; biogenic emission
; boundary layer
; canopy exchange
; extreme event
; forest canopy
; gas transport
; momentum transfer
; volatile organic compound
; wind tunnel
; altitude
; anemometer
; Article
; boundary layer
; canopy
; forest
; gas analysis
; gas analysis equipment
; priority journal
; vegetation
; vegetation canopy
; velocity
; wind
; wind tunnel
; Boundaries
; Concentration
; Forest Canopy
; Turbulence
; Voc
Scopus学科分类: Environmental Science: Water Science and Technology
; Earth and Planetary Sciences: Earth-Surface Processes
; Environmental Science: Environmental Chemistry
英文摘要: Coherent structures dominate the shear flow in and above the vegetation canopy, affecting the transport of passive scalars. Their detailed understanding is therefore of great interest for a number of environmental studies such as organic gas exchange, pollution dispersion, or forest fire propagation. In the present study, a forest embedded in an atmospheric boundary layer was reproduced in a wind tunnel. An area source was installed to mimic the volatile organic compounds emission coming from the vegetation. A fast gas analyser combined to a triple hot-wire anemometer were used to measure simultaneously and at the same point the momentum and the concentration fluxes above the canopy. This particular set-up enabled the complex scalar exchange mechanism to be studied in the well defined and stationary boundary conditions of a laboratory experiment simulating neutral atmospheric conditions. Measurements showed that the contribution of coherent structures to the momentum and the concentration flux was 80% and 60% respectively. Contributions were found to be nearly constant with height. The combination of velocity and concentration measurements enabled the determination of the mean concentration of the coherent structures. Results highlights the preponderant role of ejections in releasing highly concentrated gas pockets above the forest canopy. These releases were measured to be, in average, 40% more concentrated than the average gas concentration at the same height. It is shown that 70% of the extreme events observed are linked to an ejection process. © 2015 Elsevier Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/81931
Appears in Collections: 气候变化事实与影响
There are no files associated with this item.
作者单位: Univ. Orléans, INSA-CVL, PRISME, EA 4229, Orléans, France; INSA-CVL, Univ. Orléans, PRISME, EA 4229, Bourges, France; Institut P', UPR 3346 CNRS, ENSMA, Univ. Poitier, Chasseneuil, France
Recommended Citation:
Conan B,, Aubrun S,, Coudour B,et al. Contribution of coherent structures to momentum and concentration fluxes over a flat vegetation canopy modelled in a wind tunnel[J]. Atmospheric Environment,2015-01-01,107