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Published June 14, 2024 | Published
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Probing Iceland's dust-emitting sediments: particle size distribution, mineralogy, cohesion, Fe mode of occurrence, and reflectance spectra signatures

González-Romero, Adolfo1, 2, 3 ORCID icon
González-Flórez, Cristina1, 3 ORCID icon
Panta, Agnesh4 ORCID icon
Yus-Díez, Jesús5 ORCID icon
Córdoba, Patricia2 ORCID icon
Alastuey, Andres2 ORCID icon
Moreno, Natalia2 ORCID icon
Kandler, Konrad4 ORCID icon
Klose, Martina6 ORCID icon
Clark, Roger N.7 ORCID icon
Ehlmann, Bethany L.8 ORCID icon
Greenberger, Rebecca N.8 ORCID icon
Keebler, Abigail M.8
Brodrick, Phil9 ORCID icon
Green, Robert O.9 ORCID icon
Querol, Xavier2 ORCID icon
Pérez García-Pando, Carlos1, 10 ORCID icon
  • 1. ROR icon Barcelona Supercomputing Center
  • 2. ROR icon Institute of Environmental Assessment and Water Research
  • 3. ROR icon Universitat Politècnica de Catalunya
  • 4. ROR icon TU Darmstadt
  • 5. ROR icon University of Nova Gorica
  • 6. ROR icon Karlsruhe Institute of Technology
  • 7. ROR icon Planetary Science Institute
  • 8. ROR icon California Institute of Technology
  • 9. ROR icon Jet Propulsion Lab
  • 10. ROR icon Institució Catalana de Recerca i Estudis Avançats

Abstract

Characterising the physico-chemical properties of dust-emitting sediments in arid regions is fundamental to understanding the effects of dust on climate and ecosystems. However, knowledge regarding high-latitude dust (HLD) remains limited. This study focuses on analysing the particle size distribution (PSD), mineralogy, cohesion, iron (Fe) mode of occurrence, and visible–near infrared (VNIR) reflectance spectra of dust-emitting sediments from dust hotspots in Iceland (HLD region). Extensive analysis was conducted on samples of top sediments, sediments, and aeolian ripples collected from seven dust sources, with particular emphasis on the Jökulsá basin, encompassing the desert of Dyngjunsandur. Both fully and minimally dispersed PSDs and their respective mass median particle diameters revealed remarkable similarities (56 ± 69 and 55 ± 62 µm, respectively). Mineralogical analyses indicated the prevalence of amorphous phases (68 ± 26 %), feldspars (17 ± 13 %), and pyroxenes (9.3 ± 7.2 %), consistent with thorough analyses of VNIR reflectance spectra. The Fe content reached 9.5 ± 0.40 wt %, predominantly within silicate structures (80 ± 6.3 %), complemented by magnetite (16 ± 5.5 %), hematite/goethite (4.5 ± 2.7 %), and readily exchangeable Fe ions or Fe nano-oxides (1.6 ± 0.63 %). Icelandic top sediments exhibited coarser PSDs compared to the high dust-emitting crusts from mid-latitude arid regions, distinctive mineralogy, and a 3-fold bulk Fe content, with a significant presence of magnetite. The congruence between fully and minimally dispersed PSDs underscores reduced particle aggregation and cohesion of Icelandic top sediments, suggesting that aerodynamic entrainment of dust could also play a role upon emission in this region, alongside saltation bombardment. The extensive analysis in Dyngjusandur enabled the development of a conceptual model to encapsulate Iceland's rapidly evolving high dust-emitting environments.

Copyright and License

© Author(s) 2024. This work is distributed under the Creative Commons Attribution 4.0 License.

Published by Copernicus Publications on behalf of the European Geosciences Union.

Acknowledgement

The field campaign and its associated research, including this work, was funded by the European Research Council under the Horizon 2020 research and innovation programme through the ERC Consolidator Grant FRAGMENT (grant agreement no. 773051) and the AXA Research Fund through the AXA Chair on Sand and Dust Storms at BSC. Cristina González-Flórez was supported by a PhD fellowship from the Agència de Gestió d'Ajuts Universitaris i de Recerca (AGAUR) grant no. 2020_FI B 00678. Konrad Kandler was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) grant nos. 264907654 and 416816480. Martina Klose has received funding through the Helmholtz Association's Initiative and Networking Fund (grant agreement no. VH-NG-1533). We acknowledge the EMIT project, which is supported by the NASA Earth Venture Instrument programme, under the Earth Science Division of the Science Mission Directorate. We thank Eva L. Scheller for the help during the field spectroscopy measurements. We thank Pavla Dagsson Waldhauserova from the Agricultural University of Iceland for the invaluable support and help during the field campaign. We thank Thomas Dirsch for the uncountable driving hours and mechanical support during the soil sampling. We thank Paul Ginoux for providing high-resolution global dust source maps, which were very helpful for the identification of the FRAGMENT experimental sites. We thank the staff from the ranger station at Dreki as well as the wardens of the Dreki campsite and the Dreki mountain rescue service for their valuable support and advice. We also thank Vilhjalmur Vernharðsson and his crew from Fjalladyìrð for their permanent logistic help. Without all of them, the measurement campaign would not have been successfully feasible.

Funding

This research has been supported by the European Research Council, EU H2020 European Research Council (grant no. 773051), the AXA Research Fund (AXA Chair on Sand and Dust Storms), the Agència de Gestió d'Ajuts Universitaris i de Recerca (grant no. 2020_FI B 00678), the Deutsche Forschungsgemeinschaft (grant nos. 264907654 and 416816480), and the Helmholtz Association (grant no. VH-NG-1533).

The article processing charges for this open-access publication were covered by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI).

Contributions

CPGP proposed and designed the field campaign with contributions of AA, KK, MK, and XQ. The campaign was implemented by CPGP, AA, CGF, AGR, KK, MK, AP, XQ, and JYD. The samples were collected by CPGP, AA, AGR, MK, AMK, RNG, ROG, and XQ and analysed by AGR, PC, and NM. Spectroscopy was analysed by AMK, ROG, BLE, PB, and RNC. AGR performed the visualisation and writing of the original draft manuscript, and CPGP and XQ supervised the work. CPGP and XQ re-edited the manuscript, and all authors contributed in data discussion, reviewing, and manuscript finalisation.

Data Availability

Data used in this paper are given in the main paper itself and in the Supplement. If needed, data are also available upon request by emailing the authors.

Code Availability

The code used in this paper is provided by Clark (2024, https://doi.org/10.5281/zenodo.11204505).

Supplemental Material

The supplement related to this article is available online at: https://doi.org/10.5194/acp-24-6883-2024-supplement.

Conflict of Interest

At least one of the (co-)authors is a member of the editorial board of Atmospheric Chemistry and Physics. The peer-review process was guided by an independent editor, and the authors also have no other competing interests to declare.

Additional Information

This paper was edited by Stelios Kazadzis and reviewed by two anonymous referees.

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