Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.509 IF 5.509
  • IF 5-year value: 5.689 IF 5-year 5.689
  • CiteScore value: 5.44 CiteScore 5.44
  • SNIP value: 1.519 SNIP 1.519
  • SJR value: 3.032 SJR 3.032
  • IPP value: 5.37 IPP 5.37
  • h5-index value: 86 h5-index 86
  • Scimago H index value: 161 Scimago H index 161
Discussion papers
https://doi.org/10.5194/acp-2018-725
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-2018-725
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.

Research article 15 Aug 2018

Research article | 15 Aug 2018

Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Atmospheric Chemistry and Physics (ACP).

Mineralogy and mixing state of North African mineral dust by on-line single-particle mass spectrometry

Nicholas A. Marsden1, Romy Ullrich2, Ottmar Möhler2, Stine Eriksen Hammer3, Konrad Kandler3, Zhiqiang Cui4, Paul I. Williams1,5, Michael J. Flynn1, Dantong Liu1, James D. Allan1,5, and Hugh Coe1 Nicholas A. Marsden et al.
  • 1School of Earth and Environmental Sciences, University of Manchester, UK
  • 2Institute of Meteorology and Climate Research, Karlsruhe Institute of Technology, Germany
  • 3Institute of Applied Geosciences, Technische Universitat Darmstadt, Germany
  • 4School of Earth and Environment, University of Leeds, UK
  • 5National Centre for Atmospheric Science, Manchester, UK

Abstract. The mineralogy and mixing state of dust particles originating from the African continent influences climate and marine ecosystems in the North Atlantic due to its effect on radiation, cloud properties and biogeochemical cycling. Single-particle mineralogy and mixing state is particularly important in many processes but is difficult to predict because of large temporal and spatial variability and the lack of in-situ measurements of dust properties during emission, transport and deposition. This lack of measurements is in part due to the remoteness of potential source areas (PSA) and transport pathways, but also because of the lack of an efficient method to report the mineralogy and mixing state of single particles with a time resolution comparable to atmospheric processes.

In this work, the mineralogy and mixing state of the fine fraction (<2.5μm) in laboratory suspended dust from the Sahara and Sahel were made using novel techniques with on-line single-particle mass spectrometry (SPMS) and traditional off-line scanning electron microscopy (SEM). A regional difference in mineralogy was detected, with material sourced from Morocco contained a high number fraction of illite like particles in contrast to Sahelian material which contains potassium and sodium depleted clay minerals like kaolinite. Applying the same methods to ambient measurement of transported dust in the marine boundary layer at Cabo Verde in the remote North Atlantic enabled the number fractions of illite/smectite clay mineral (ISCM), non-ISCM, and calcium containing particles to be reported at a 1 hour time resolution over a 20 day period alongside internal mixing with nitrate, sulphate and organic/biological material. The ISCM and nitrate content was found to change significantly between distinct dust events, indicating a shift in source and transport pathways which may not be captured in off-line composition analysis or remote sensing techniques.

The results show SPMS and SEM techniques are complimentary and demonstrate that SPMS can provide a meaningful high resolution measurement of single-particle mineralogy and mixing state in laboratory and ambient conditions. In most cases, the mineralogy varies continuously between particles rather than a collection of discrete mineral phases. These techniques will be useful in resolving the complexity of mineral dust transport and in obtaining atmospherically relevant test material for laboratory experiments of dust properties.

Nicholas A. Marsden et al.
Interactive discussion
Status: final response (author comments only)
Status: final response (author comments only)
AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment
[Login for Authors/Co-Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement
Nicholas A. Marsden et al.
Nicholas A. Marsden et al.
Viewed
Total article views: 474 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
351 116 7 474 22 8 9
  • HTML: 351
  • PDF: 116
  • XML: 7
  • Total: 474
  • Supplement: 22
  • BibTeX: 8
  • EndNote: 9
Views and downloads (calculated since 15 Aug 2018)
Cumulative views and downloads (calculated since 15 Aug 2018)
Viewed (geographical distribution)
Total article views: 474 (including HTML, PDF, and XML) Thereof 470 with geography defined and 4 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Cited
Saved
No saved metrics found.
Discussed
No discussed metrics found.
Latest update: 15 Nov 2018
Publications Copernicus
Special issue
Download
Short summary
The composition of airborne dust influences climate and ecosystems but its measurements presents a huge analytical challenge. Using online single particle mass spectrometry, we demonstrate differences in mineralogy and mixing state can be detected in real-time in both laboratory studies and ambient measurements. The results provide insights into the temporal and spatial evolution of dust properties that will be useful for aerosol-cloud interaction studies and dust cycle modelling.
The composition of airborne dust influences climate and ecosystems but its measurements presents...
Citation
Share