Preprints
https://doi.org/10.5194/egusphere-2024-157
https://doi.org/10.5194/egusphere-2024-157
22 Jan 2024
 | 22 Jan 2024

Probing Iceland's Dust-Emitting Sediments: Particle Size Distribution, Mineralogy, Cohesion, Fe Mode of Occurrence, and Reflectance Spectra Signatures

Adolfo González-Romero, Cristina González-Flórez, Agnesh Panta, Jesús Yus-Díez, Patricia Córdoba, Andres Alastuey, Natalia Moreno, Konrad Kandler, Martina Klose, Roger N. Clark, Bethany L. Ehlmann, Rebecca N. Greenberger, Abigail M. Keebler, Phil Brodrick, Robert O. Green, Xavier Querol, and Carlos Pérez García-Pando

Abstract. Characterizing physico-chemical properties of dust-emitting sediments in arid regions is fundamental to understand the effect of dust on climate and ecosystems. For high-latitude dust (HLD), this knowledge is scarce. This study focuses on the particle size distribution (PSD), mineralogy, cohesion, iron (Fe) mode of occurrence and Visible Near Infra-Red (VNIR) reflectance spectra of dust-emitting sediments from dust-hotspots in Iceland (HLD region). Extensive analysis was conducted on top sediments collected from seven dust-sources and an intensive at Jokulsá basin including top sediments, sediments and aeolian ripples. Fully and minimally dispersed PSDs evidenced remarkable similarities with an average median diameter of 56±69 and 55±62 µm. Mineralogical analyses showed the prevalence of amorphous phases (68±26 %), feldspars (17±13 %), and pyroxenes (9.3±7.2 %), aligned with the reflectance spectra. Fe content reached 9.5±0.40 wt %, mainly in 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 have coarser PSD compared to the high dust-emitting crusts from mid-latitude arid regions, distinctive mineralogy, and threefold bulk Fe content, with a large presence of magnetite. The congruence between fully and minimally dispersed PSDs underscores a reduced particle aggregation and cohesion of Icelandic top sediments, suggesting that aerodynamic entrainment of dust may also play a role upon emission in this region, aside of saltation bombardment. The analysis of an extensive sampling in Dyngjusandur allowed this study to present a conceptual model to encapsulate Iceland's rapidly evolving high dust-emitting environments.

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Journal article(s) based on this preprint

14 Jun 2024
Probing Iceland's dust-emitting sediments: particle size distribution, mineralogy, cohesion, Fe mode of occurrence, and reflectance spectra signatures
Adolfo González-Romero, Cristina González-Flórez, Agnesh Panta, Jesús Yus-Díez, Patricia Córdoba, Andres Alastuey, Natalia Moreno, Konrad Kandler, Martina Klose, Roger N. Clark, Bethany L. Ehlmann, Rebecca N. Greenberger, Abigail M. Keebler, Phil Brodrick, Robert O. Green, Xavier Querol, and Carlos Pérez García-Pando
Atmos. Chem. Phys., 24, 6883–6910, https://doi.org/10.5194/acp-24-6883-2024,https://doi.org/10.5194/acp-24-6883-2024, 2024
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The requested preprint has a corresponding peer-reviewed final revised paper. You are encouraged to refer to the final revised version.

Short summary
The knowledge of properties from dust emitted in high latitudes as Iceland (HLD) is scarce. This...
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