Size-Resolved Dry Deposition Velocities of Dust Particles: In Situ Measurements and Parameterizations Testing - Archive ouverte HAL Access content directly
Journal Articles Journal of Geophysical Research: Atmospheres Year : 2018

Size-Resolved Dry Deposition Velocities of Dust Particles: In Situ Measurements and Parameterizations Testing

Abstract

Bulk and size-resolved particle concentrations were measured at 2.1 and 6.5 m above the soil surface during an intense dust deposition event that occurred in June 2006 in Niger. Bulk concentration measurements were performed using two tapered element oscillating microbalance instruments, and the size-resolved particle concentrations (from 0.3 to 20 μm) using two optical particle counters. The deposition fluxes derived from the bulk concentrations and those derived from the size-resolved ones are in very good agreement. The largest deposition fluxes are recorded when the dust concentrations are maximal. The temporal evolution of the dust deposition flux follows that of the dust concentration. This is not the case of the dry deposition velocities that are most of the time controlled by the wind friction velocity. The results also show that large particles are strongly sensible to rebound when the wind friction velocity is the highest. Size-resolved dry deposition velocities are compared with the rare measurements of dust deposition velocities over bare sandy soils and are confronted to existing parameterizations of the dry deposition velocity. The parameterization of Zhang and Shao (2014, https://doi.org/10.5194/acp-14-12429-2014) appears to be the only one able to reproduce satisfyingly the measured dry deposition velocities on sandy soils in the 1-to 10-μm particle size range. Indeed, unlike others, this scheme considers the desert sandy surfaces as rough surfaces, allowing the interception of dust particles by the sand grains and/or by the small roughness elements present on the surface.
Fichier principal
Vignette du fichier
bergametti et al., JGR, 2018.pdf (2.41 Mo) Télécharger le fichier
Origin : Publisher files allowed on an open archive
Loading...

Dates and versions

hal-02323364 , version 1 (21-10-2019)

Identifiers

Cite

G. Bergametti, B. Marticoréna, J. L Rajot, Gilles Foret, S. Alfaro, et al.. Size-Resolved Dry Deposition Velocities of Dust Particles: In Situ Measurements and Parameterizations Testing. Journal of Geophysical Research: Atmospheres, 2018, 123 (19), pp.11,080-11,099. ⟨10.1029/2018JD028964⟩. ⟨hal-02323364⟩
71 View
114 Download

Altmetric

Share

Gmail Facebook X LinkedIn More