Open AccessSensitivity of mineral dust concentrations to the model size distribution accuracy
Author(s) -
Menut Laurent,
Forêt Gilles,
Bergametti Gilles
Publication year - 2007
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006jd007766
Subject(s) - mm5 , bin , environmental science , mesoscale meteorology , sensitivity (control systems) , deposition (geology) , mineral dust , particle size distribution , meteorology , particle size , atmospheric sciences , geology , mathematics , algorithm , physics , aerosol , geomorphology , sediment , paleontology , electronic engineering , engineering
Evaluating the impacts of atmospheric dust on marine ecosystems and climate requires the use of three‐dimensional transport models including a size‐resolved bins scheme to describe the evolution of the particle size distribution. Recently, Forêt et al. (2006) proposed an alternative size bins scheme to better account for the physical size‐dependent processes such as dry deposition. This paper evaluates the benefit of using this new bin scheme in three‐dimensional transport models. This is achieved by performing a one‐and‐a‐half month simulation with the CHIMERE‐DUST model forced by the Mesoscale Model, Version 5 (MM5)/National Center for Environmental Prediction (NCEP) analysis fields, for an area covering the northern Atlantic Sea and the western Africa. Compared to a reference run performed using a large number of size bins (40), our results show that the size bins scheme proposed by Forêt et al. (2006) reduces at least by a factor of 2 the numerical errors on the simulated concentrations compared to the classical isolog bins scheme for the same number of size bins. However, with this new bins scheme requiring to define the bins according to a dry deposition velocity corresponding to a given friction velocity, we examine the errors associated to this constraint.