DOI: 10.1002/jgrd.50528
论文题名: Modeling saltation intermittency
作者: Dupont S. ; Bergametti G. ; Marticorena B. ; Simoëns S.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 13 起始页码: 7109
结束页码: 7128
语种: 英语
英文关键词: aeolian streamer
; erosion
; large eddy simulation
; saltation
Scopus关键词: Computer simulation
; Erosion
; Light transmission
; Velocity
; aeolian streamer
; Correlation analysis
; Large-eddy simulation models
; Median particle diameters
; Particle response time
; Saltating particles
; saltation
; Surface boundary-layer
; Large eddy simulation
; atmospheric modeling
; correlation
; data set
; eddy
; eolian deposit
; erosion
; numerical model
; particle size
; saltation
; turbulent boundary layer
; velocity
; visualization
英文摘要: In order to investigate the intermittency of the aeolian saltation, a saltation model, forced with instantaneous velocity fields, has been introduced in a Large Eddy Simulation airflow model. The coupled model is evaluated on a flat erodible surface under various wind conditions and soil particle-size distribution. It is first shown that the model is able to simulate a well-developed saltation layer in equilibrium with the turbulent flow. The main characteristics of the saltation layer and their sensitivity to wind conditions are in good agreement with previous data set. Then, the saltation intermittency is visualized through the presence of blowing sand structures near the surface, known as aeolian streamers. This is the first time that such structures are reproduced numerically. From a correlation analysis, we confirm previous thoughts that these sand structures are a visual footprint of past turbulent eddies propagating in the surface boundary layer. The streamers appear to be embedded in larger saltation structures with increasing wind conditions. The spatial scales of these streamers change with wind conditions and soil particle-size distribution. This is explained by two mechanisms: (1) the modification of eddy structures with the main characteristics of the saltation layer, and (2) the reduction of saltating particle sensitivity to the near-surface eddies with increasing wind condition and soil median particle diameter, as the eddy lifetime decreases within the saltation layer and the particle response time increases, respectively. The standard deviation of the saltation flux associated to these saltation patterns represents about 10% to 20% of the mean saltation flux. Key Points A novel saltation model is developed in a Large-Eddy Simulation model Aeolian streamers are reproduced numerically Aeolian streamers are explained by flow eddies ©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/63569
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: INRA, UR1263 Ephyse, 71 Avenue Edouard Bourlaux, FR-33140 Villenave d'Ornon, France; LISA (Laboratoire Interuniversitaire des Systèmes Atmosphériques), UMR CNRS 7583, Universités Paris Diderot and Paris Est, Créteil, France; LMFA, Ecole Centrale de Lyon, Université de Lyon i, INSA Lyon, France
Recommended Citation:
Dupont S.,Bergametti G.,Marticorena B.,et al. Modeling saltation intermittency[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(13)