scholarly journals The characteristics of African easterly waves coupled to Saharan mineral dust aerosols

2019 ◽  
Vol 145 (720) ◽  
pp. 1130-1146 ◽  
Author(s):  
Dustin F.P. Grogan ◽  
Christopher D. Thorncroft
Keyword(s):  
Mineral Dust ◽  
African Easterly Waves ◽  
Easterly Waves ◽  
Dust Aerosols ◽  
Mineral Dust Aerosols

scholarly journals Modelling lidar-relevant optical properties of complex mineral dust aerosols

Tellus B ◽  
2011 ◽  
Vol 63 (4) ◽  
pp. 725-741 ◽  
Author(s):  
Josef Gasteiger ◽  
Matthias Wiegner ◽  
Silke Groß ◽  
Volker Freudenthaler ◽  
Carlos Toledano ◽  
...  
Keyword(s):  
Optical Properties ◽  
Mineral Dust ◽  
Dust Aerosols ◽  
Mineral Dust Aerosols

Properties and challenges of mineral dust aerosol modelling in the latest Earth System Models

2020 ◽  
Author(s):  
Ramiro Checa-Garcia ◽  
Yves Balkanski ◽  
Tommi Bergman ◽  
Ken Carslaw ◽  
Mohit Dalvi ◽  
...  
Keyword(s):  
Optical Depth ◽  
Mineral Dust ◽  
Regional Scale ◽  
Climate System ◽  
Deposition Flux ◽  
Dust Aerosols ◽  
Earth Systems ◽  
Imperfect Knowledge ◽  
Sahel Region ◽  
Mineral Dust Aerosols

<p>Mineral dust aerosols participate in the climate system and biogeochemistry processes due to its interactions with key components of Earth Systems: radiation, clouds, soil and chemical components. A central element to improve our understanding of mineral dust is through its modeling with Earth Systems Models where all these interactions are included. However, current simulations of dust variability exhibit important uncertainties and biases, which are model-dependent, whose cause is our imperfect knowledge about how to best represent the dust life cycle. For these reasons a continuous evaluation of the performance and properties of the different models compared against measurements is a crucial step to improve our knowledge of the dust cycle and its role in the climate system and biogeochemical cycles. Here we present an exhaustive evaluation of mineral dust aerosols in CRESCEND-ESMs over global, regional and local scales. We compare models against three networks of instruments for total dust deposition flux, yearly surface concentrations, and optical depths. Global and regional dust optical depths are compared with MODIS and MISR derived products. Specific analyses are done over the Sahel region where improved and compressive dust observational datasets are available. The results indicate that all the models capture the general properties of the global dust cycle, although the role of larger particles remains challenging. Differences are partially due to surface winds as nudged simulations improve the inter-model comparison and the performance in optical depth compared to MODIS. At the regional scale, there is an optical depth reasonable agreement over main source areas, but a joint inter-comparison including fluxes and concentration indicates larger differences. At the local scale, the uncertainties increase and current models are not able to reproduce together several observables at the same time.</p>

A method to determine the effect of mineral dust aerosols on air quality

2009 ◽  
Vol 43 (34) ◽  
pp. 5463-5468 ◽  
Author(s):  
Eliezer Ganor ◽  
Amnon Stupp ◽  
Pinhas Alpert
Keyword(s):  
Air Quality ◽  
Mineral Dust ◽  
Dust Aerosols ◽  
Mineral Dust Aerosols

scholarly journals Characterization of iron oxides in mineral dust aerosols: Implications for light absorption

2006 ◽  
Vol 111 (D21) ◽  
Author(s):  
Sandra Lafon ◽  
Irina N. Sokolik ◽  
Jean Louis Rajot ◽  
Sandrine Caquineau ◽  
Annie Gaudichet
Keyword(s):  
Iron Oxides ◽  
Light Absorption ◽  
Mineral Dust ◽  
Dust Aerosols ◽  
Mineral Dust Aerosols

Subcritical Destabilization of African Easterly Waves by Saharan Mineral Dust

2017 ◽  
Vol 74 (4) ◽  
pp. 1039-1055 ◽  
Author(s):  
Terrence R. Nathan ◽  
Dustin F. P. Grogan ◽  
Shu-Hua Chen
Keyword(s):  
Mineral Dust ◽  
Baroclinic Instability ◽  
Wrf Model ◽  
Phase Speed ◽  
Theoretical Framework ◽  
Linear Instability ◽  
Wave Activity ◽  
African Easterly Waves ◽  
Easterly Waves ◽  
Coupled Equations

Abstract A theoretical framework is presented that exposes the radiative–dynamical relationships that govern the subcritical destabilization of African easterly waves (AEWs) by Saharan mineral dust (SMD) aerosols. The framework is built on coupled equations for quasigeostrophic potential vorticity (PV), temperature, and SMD mixing ratio. A perturbation analysis yields, for a subcritical, but otherwise arbitrary, zonal-mean background state, analytical expressions for the growth rate and frequency of the AEWs. The expressions are functions of the domain-averaged wave activity, which is generated by the direct radiative effects of the SMD. The wave activity is primarily modulated by the Doppler-shifted phase speed and the background gradients in PV and SMD. Using an idealized version of the Weather Research and Forecasting (WRF) Model coupled to an interactive dust model, a linear analysis shows that, for a subcritical African easterly jet (AEJ) and a background SMD distribution that are consistent with observations, the SMD destabilizes the AEWs and slows their westward propagation, in agreement with the theoretical prediction. The SMD-induced growth rates are commensurate with, and can sometimes exceed, those obtained in previous dust-free studies in which the AEWs grow on AEJs that are supercritical with respect to the threshold for barotropic–baroclinic instability. The clarity of the theoretical framework can serve as a tool for understanding and predicting the effects of SMD aerosols on the linear instability of AEWs in subcritical, zonal-mean AEJs.

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