DOI: 10.1002/jgrd.50625
论文题名: The role of coherent flow structures in the sensible heat fluxes of an Alaskan boreal forest
作者: Starkenburg D. ; Fochesatto G.J. ; Prakash A. ; Cristõbal J. ; Gens R. ; Kane D.L.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 15 起始页码: 8140
结束页码: 8155
语种: 英语
英文关键词: Boreal forests
; Coherent turbulence
; Flux efficiency
; Heterogeneous surface
; Turbulent fluxes
; Wavelet analysis
Scopus关键词: Heat flux
; Wavelet analysis
; Black spruce boreal forests
; Boreal forests
; Coherent structure
; Fairbanks , Alaska
; Global statistics
; Heterogeneous surface
; Sensible heat flux
; Turbulent flux
; Forestry
; acceleration
; boreal forest
; canopy
; flow structure
; heterogeneity
; seasonal variation
; sensible heat flux
; temperature effect
; turbulence
; wavelet analysis
; Alaska
; United States
; Picea mariana
英文摘要: Accelerations in the flow over forests generate coherent structures which locally enhance updrafts and downdrafts, forcing rapid exchanges of energy and matter. Here, observations of the turbulent flow are made in a highly heterogeneous black spruce boreal forest in Fairbanks, Alaska at ~2.6 h (12 m) and ~0.6 h (3 m), where h is the mean canopy height of 4.7 m. Wavelet analysis is used to detect coherent structures. The sonic temperature and wind data cover 864 half-hour periods spanning winter, spring, and summer. When mean global statistics of structures are analyzed at the two levels independently, results are similar to other studies. Specifically, an average of eight structures occurs per period, their mean duration is 85 s, and their mean heat flux contribution is 48%. However, this analysis suggests that 31% of the structures detected at 2.6 h, and 13% at 0.6 h, may be influenced by wave-like flow organization. Remarkably, less than 25% of the structures detected occur synchronously in the subcanopy and above canopy levels, which speaks robustly to the lack of flow interaction within only nine vertical meters of the forest. Key Points Coherent structures in Alaskan boreal forest are similar to other sites 30% of the structures above the canopy may be influenced by gravity waves Most coherent structures are confined to one level in this Alaskan boreal forest ©2013. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63425
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Atmospheric Sciences, College of Natural Sciences and Mathematics, University of Alaska Fairbanks, 903 Koyukuk Dr., Fairbanks, AK 99775-7320, United States; Geophysical Institute, University of Alaska Fairbanks, Fairbanks AK, United States; Water Environmental Research Center, University of Alaska Fairbanks, Fairbanks AK, United States
Recommended Citation:
Starkenburg D.,Fochesatto G.J.,Prakash A.,et al. The role of coherent flow structures in the sensible heat fluxes of an Alaskan boreal forest[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(15)