Quantifying uncertainty in estimates of mineral dust flux: An intercomparison of model performance over the Bodélé Depression, northern Chad

Martin C. Todd (1) , Diana Bou Karam (2) , C. Cavazos (1) , Christel Bouet (3) , B. Heinold (4) , J.M. Baldasano (5) , Guy Cautenet (3, 6) , I. Koren (7) , C. Perez (5) , Fabien Solmon (8) , I. Tegen (4) , Pierre Tulet (9) , R. Washington (10) , A. Zakey (11)

1 UCL Department of Geography
2 SA - Service d'aéronomie
3 LaMP - Laboratoire de météorologie physique
4 TROPOS - Leibniz Institute for Tropospheric Research
5 Earth Sciences Department [Barcelona]
6 Laboratory of Environmental Modelling
7 Weizmann Institute of Science [Rehovot, Israël]
8 LAERO - Laboratoire d'aérologie
9 Équipe Troposphère
10 OUCE - Oxford University Centre for the Environment
11 ICTP - Abdus Salam International Centre for Theoretical Physics [Trieste]

Mineral dust aerosols play an important role in the climate system. Coupled climate-aerosol models are an important tool with which to quantify dust fluxes and the associated climate impact. Over the last decade or more, numerous models have been developed, both global and regional, but to date, there have been few attempts to compare the performance of these models. In this paper a comparison of five regional atmospheric models with dust modules is made, in terms of their simulation of meteorology, dust emission and transport. The intercomparison focuses on a 3-day dust event over the Bodélé depression in northern Chad, the world's single most important dust source. Simulations are compared to satellite data and in situ observations from the Bodélé Dust Experiment (BoDEx 2005). Overall, the models reproduce many of the key features of the meteorology and the large dust plumes that occur over the study domain. However, there is at least an order of magnitude range in model estimates of key quantities including dust concentration, dust burden, dust flux, and aerosol optical thickness. As such, there remains considerable uncertainty in model estimates of the dust cycle and its interaction with climate. This paper discusses the issues associated with partitioning various sources of model uncertainty.

Mots clés: Mineral dust; dust models; Bodélé Depression

Domaines: Climatologie; Milieux et Changements globaux; Physique Atmosphérique et Océanique [physics.ao-ph]

Martin C. Todd, Diana Bou Karam, C. Cavazos, Christel Bouet, B. Heinold, et al.. Quantifying uncertainty in estimates of mineral dust flux: An intercomparison of model performance over the Bodélé Depression, northern Chad. Journal of Geophysical Research: Atmospheres, 2008, 113 (D24), pp.D24107. ⟨10.1029/2008JD010476⟩. ⟨hal-00348062⟩