Southern African dust aerosols are rich in micronutrients, K-feldspar and carbonate minerals

Abstract. This study provides the first comprehensive characterisation of the chemical and mineralogical composition of mineral dust from Southern Africa, a major global dust source with significant impacts on regional climate and marine ecosystems. Laboratory-generated dust aerosol samples were produced using soils collected from key natural and emerging anthropogenic dust sources in Southern Africa. The chemical properties of mineral dust across Southern Africa were characterised using the elemental ratios Si/Al, (Ca+Mg)/Al, and K/Al, together with clay content. These indicators distinguish dust aerosols originating from arid western coastal areas from those originating from more humid eastern inland regions. They also provide information about the source-area environments and sediment weathering regimes, which are influenced by current and past temperature and precipitation patterns. The results of this study indicate that Southern African dust contains essential micronutrients such as iron (Fe), phosphorus (P) and manganese (Mn), which can become soluble and bioaccessible during atmospheric transport. In particular, emerging anthropogenic dust can be distinguished by its high content of certain nutrients. This affects the biogeochemistry of nearby and remote marine ecosystems, including the Southern Ocean. Southern African dust also contains higher levels of carbonates than Northern African dust sources, which can promote heterogeneous reactions and particle ageing, and contribute to cloud condensation nuclei in the extensive stratocumulus deck over the northern Benguela Upwelling System. Our findings also suggest that Southern African dust contains higher levels of K-feldspar than Northern African dust, and could therefore be an important source of ice-nucleating particles for low mixed-phase clouds over the Southern Ocean.

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Publication Details

Journal
Atmospheric chemistry and physics
Published
2026-08-03
DOI
https://doi.org/10.5194/acp-26-10727-2026
Primary Topic
Atmospheric aerosols and clouds
Type
article
Field-Weighted Citation Impact
0.00

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article

Southern African dust aerosols are rich in micronutrients, K-feldspar and carbonate minerals

Gael Noyalet, Sandra Lafon, Silvia Becagli, Clarissa Baldo et al.
Atmospheric chemistry and physics
Atmospheric aerosols and clouds
article

Southern African dust aerosols are rich in micronutrients, K-feldspar and carbonate minerals

Gael Noyalet, Sandra Lafon, Silvia Becagli, Clarissa Baldo, Claudia Di Biagio, Tjaart Van der Walt, Paola Formenti, Sophie Nowak, Jean‐François Doussin, Stéphane Jacquemoud, Eugène Marais, Mathieu Cazaunau, Nadine Mattielli, Gregory S. Okin, Brigitte Language, Amélie Chaput, Akinori Ito, Remi STANUS, James King, Karine Desboeufs, Stuart Piketh, Heleen C. Vos, Edouard Pangui, Laurie Barrier, Servanne Chevaillier
article en

Abstract

Abstract. This study provides the first comprehensive characterisation of the chemical and mineralogical composition of mineral dust from Southern Africa, a major global dust source with significant impacts on regional climate and marine ecosystems. Laboratory-generated dust aerosol samples were produced using soils collected from key natural and emerging anthropogenic dust sources in Southern Africa. The chemical properties of mineral dust across Southern Africa were characterised using the elemental ratios Si/Al, (Ca+Mg)/Al, and K/Al, together with clay content. These indicators distinguish dust aerosols originating from arid western coastal areas from those originating from more humid eastern inland regions. They also provide information about the source-area environments and sediment weathering regimes, which are influenced by current and past temperature and precipitation patterns. The results of this study indicate that Southern African dust contains essential micronutrients such as iron (Fe), phosphorus (P) and manganese (Mn), which can become soluble and bioaccessible during atmospheric transport. In particular, emerging anthropogenic dust can be distinguished by its high content of certain nutrients. This affects the biogeochemistry of nearby and remote marine ecosystems, including the Southern Ocean. Southern African dust also contains higher levels of carbonates than Northern African dust sources, which can promote heterogeneous reactions and particle ageing, and contribute to cloud condensation nuclei in the extensive stratocumulus deck over the northern Benguela Upwelling System. Our findings also suggest that Southern African dust contains higher levels of K-feldspar than Northern African dust, and could therefore be an important source of ice-nucleating particles for low mixed-phase clouds over the Southern Ocean.

Atmospheric chemistry and physicsVol. 26(15)
Centre National de la Recherche Scientifique (FR), Japan Agency for Marine-Earth Science and Technology (JP), Université Libre de Bruxelles (BE), Vrije Universiteit Brussel (BE), Institut de physique du globe de Paris (FR), University of California, Los Angeles (US), National University of Singapore (SG), University of Basel (CH), Université Paris-Est Créteil (FR), Université Paris Cité (FR), Stellenbosch University (ZA), North-West University (ZA), Paris-Est Sup (FR), Sorbonne Paris Cité (FR), Gobabeb Namib Research Institute (NA), Interfaces Traitements Organisation et Dynamique des Systèmes (FR), Laboratoire Interuniversitaire des Systèmes Atmosphériques (FR), Laboratoire Techniques, Territoires et Sociétés (FR), University of Florence (IT), Université de Montréal (CA)
National Science Foundation, Agence Nationale de la Recherche, Horizon 2020
Life below water
Openalex Percentile: Top 11%
Atmospheric aerosols and clouds
DOIOpen Access PDFOpenAlex
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