气候变化领域集成服务门户(CCPortal): Influence of Atmospheric Stability on the Size Distribution of the Vertical Dust Flux Measured in Eroding Conditions Over a Flat Bare Sandy Field

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DOI	10.1029/2019JD031185
	Influence of Atmospheric Stability on the Size Distribution of the Vertical Dust Flux Measured in Eroding Conditions Over a Flat Bare Sandy Field
	Khalfallah B.; Bouet C.; Labiadh M.T.; Alfaro S.C.; Bergametti G.; Marticorena B.; Lafon S.; Chevaillier S.; Féron A.; Hease P.; Henry des Tureaux T.; Sekrafi S.; Zapf P.; Rajot J.L.
发表日期	2020
ISSN	2169897X
卷号	125 期号:4
英文摘要	In spite of their importance for the modeling of the atmospheric cycle of mineral dust, measurements of the intensity and size distribution of the dust emission flux produced by wind erosion in natural conditions remain rare. During the WIND-O-V's (WIND erOsion in presence of sparse Vegetation) 2017 experiment, eight major erosion events having occurred on a sandy flat field of southern Tunisia were documented. Consistent with the small size (90 μm) of the erodible sand grains and the low aerodynamic roughness length (Z0 < 0.079 cm), the threshold for wind erosion was low (ut = 22 cm/s). The classical gradient method was applied to assess the size-resolved vertical dust flux, and the stability of the atmosphere quantified by the means of the Richardson number (Ri) as well as of its shear stress (u) and thermal gradient (∂θ/∂z) components. The vertical dust flux increased with u* following a power law but the number size distribution of the dust flux was found to be significantly richer in submicron particles in thermally unstable than in stable periods. This challenges the usual assumption that, independently of their size, the particles smaller than 10 μm follow equally the movements of the air masses in which they are embedded and that the thermal stratification of the surface layer does not affect the size distribution of the surface flux when measured a few meters above the ground. Finally, we propose a simple empirical method for taking this influence of the thermal instability into account. ©2020. American Geophysical Union. All Rights Reserved.
英文关键词	atmospheric stability; gradient method; size-resolved dust flux; Wind erosion
语种	英语
来源期刊	Journal of Geophysical Research: Atmospheres
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186165
作者单位	LISA (Laboratoire Interuniversitaire des Systèmes Atmosphériques), UMR CNRS 7583, Université Paris Est Créteil-Université de Paris, Institut Pierre Simon Laplace, Créteil, France; iEES Paris (Institut d'Ecologie et des Sciences de l'Environnement de Paris), UMR IRD 242, Université Paris Est Créteil-Sorbonne Université-CNRS-INRA-Université de Paris, Bondy, France; IRA (Institut des Régions Arides) de Médenine, El Fjé, Tunisia
推荐引用方式 GB/T 7714	Khalfallah B.,Bouet C.,Labiadh M.T.,et al. Influence of Atmospheric Stability on the Size Distribution of the Vertical Dust Flux Measured in Eroding Conditions Over a Flat Bare Sandy Field[J],2020,125(4).
APA	Khalfallah B..,Bouet C..,Labiadh M.T..,Alfaro S.C..,Bergametti G..,...&Rajot J.L..(2020).Influence of Atmospheric Stability on the Size Distribution of the Vertical Dust Flux Measured in Eroding Conditions Over a Flat Bare Sandy Field.Journal of Geophysical Research: Atmospheres,125(4).
MLA	Khalfallah B.,et al."Influence of Atmospheric Stability on the Size Distribution of the Vertical Dust Flux Measured in Eroding Conditions Over a Flat Bare Sandy Field".Journal of Geophysical Research: Atmospheres 125.4(2020).