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Advances in Meteorology
Volume 2012 (2012), Article ID 260515, 13 pages
http://dx.doi.org/10.1155/2012/260515
Research Article

A Comparison of Two Dust Uplift Schemes within the Same General Circulation Model

1Department of Meteorology, University of Reading, Reading RG6 6BB, UK
2Monash Weather and Climate, Monash University, VIC, Clayton 3800, Australia
3National Centres for Atmospheric Science (Climate), University of Reading, Reading RG6 6BB, UK
4Met Office, Exeter EX1 3PB, UK

Received 1 December 2011; Revised 12 April 2012; Accepted 9 May 2012

Academic Editor: Ralph A. Kahn

Copyright © 2012 Duncan Ackerley et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Aeolian dust modelling has improved significantly over the last ten years and many institutions now consistently model dust uplift, transport and deposition in general circulation models (GCMs). However, the representation of dust in GCMs is highly variable between modelling communities due to differences in the uplift schemes employed and the representation of the global circulation that subsequently leads to dust deflation. In this study two different uplift schemes are incorporated in the same GCM. This approach enables a clearer comparison of the dust uplift schemes themselves, without the added complexity of several different transport and deposition models. The global annual mean dust aerosol optical depths (at 550 nm) using two different dust uplift schemes were found to be 0.014 and 0.023—both lying within the estimates from the AeroCom project. However, the models also have appreciably different representations of the dust size distribution adjacent to the West African coast and very different deposition at various sites throughout the globe. The different dust uplift schemes were also capable of influencing the modelled circulation, surface air temperature, and precipitation despite the use of prescribed sea surface temperatures. This has important implications for the use of dust models in AMIP-style (Atmospheric Modelling Intercomparison Project) simulations and Earth-system modelling.