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: 5.414 IF 5.414
  • IF 5-year value: 5.958 IF 5-year
  • CiteScore value: 9.7 CiteScore
  • SNIP value: 1.517 SNIP 1.517
  • IPP value: 5.61 IPP 5.61
  • SJR value: 2.601 SJR 2.601
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 191 Scimago H
    index 191
  • h5-index value: 89 h5-index 89
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

  04 Jun 2020

04 Jun 2020

Review status
This preprint is currently under review for the journal ACP.

Mixing states of Amazon-basin aerosol particles transported over long distances using transmission electron microscopy

Kouji Adachi1, Naga Oshima1, Zhaoheng Gong2,a, Suzane de Sá2, Adam P. Bateman2, Scot T. Martin2, Joel F. de Brito3,b, Paulo Artaxo3, Glauber G. Cirino4,c, Arthur J. Sedlacek III5, and Peter R. Buseck6 Kouji Adachi et al.
  • 1Department of Atmosphere, Ocean and Earth System Modelling Research, Meteorological Research Institute, Tsukuba, Japan
  • 2School of Engineering and Applied Sciences & Department of Earth and Planetary Sciences, Harvard University, Cambridge, Massachusetts, USA
  • 3Institute of Physics, University of São Paulo, São Paulo, Brazil
  • 4National Institute for Amazonian Research, Manaus, Amazonas, Brazil
  • 5Brookhaven National Laboratory, Upton, New York, USA
  • 6School of Earth and Space Exploration & School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA
  • anow at: Harvard Business School, Boston, Massachusetts, USA
  • bnow at: IMT Lille Douai, University of Lille,SAGE, Lille 59000, France
  • cnow at: Geosciences Institute, Federal University of Para, Belem, Brazil

Abstract. The Amazon basin is important for understanding the global climate both because of its carbon cycle and as a laboratory for obtaining basic knowledge of the continental background atmosphere. Aerosol particles play an important role in the climate and weather, and knowledge of their compositions and mixing states is necessary to understand their influence on the climate. For this study, we collected aerosol particles from the Amazon basin during the Green Ocean Amazon (GoAmazon2014/5) campaign (February to March 2014) at the T3 site, which locates about 70 km from Manaus, and analyzed using transmission electron microscopy (TEM). TEM has better spatial resolution than other instruments, which enables us to analyse the occurrences of components that attach to or are embedded within other particles. Based on the TEM results of more than 10,000 particles from several transport events, this study shows the occurrences of individual particles including compositions, size distributions, number fractions, and possible sources of materials that mix with other particles. Aerosol particles during the wet season were from both natural sources such as the Amazon forest, Saharan desert, Atlantic Ocean, and African biomass burning and anthropogenic sources such as Manaus and local emissions. These particles mix together at an individual particle scale. The number fractions of mineral dust and sea-salt particles increased almost three-fold when long-range transport (LRT) from the African continent occurred. Nearly 20 % of mineral dust and primary biological aerosol particles attached sea salts on their surfaces. Sulfates were also internally mixed with sea-salt and mineral dust particles. The TEM element mapping images showed that several components with sizes of hundreds of nanometres from different sources commonly occur within individual LRT aerosol particles. We conclude that many aerosol particles from natural sources change their compositions by mixing during transport. The compositions and mixing states of these particles after emission result in changes in their hygroscopic and optical properties and should be considered when assessing their effects on climate.

Kouji Adachi 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/Editors] [Subscribe to comment alert] Printer-friendly Version - Printer-friendly version Supplement - Supplement

Kouji Adachi et al.

Kouji Adachi et al.


Total article views: 206 (including HTML, PDF, and XML)
HTML PDF XML Total Supplement BibTeX EndNote
132 67 7 206 12 9 6
  • HTML: 132
  • PDF: 67
  • XML: 7
  • Total: 206
  • Supplement: 12
  • BibTeX: 9
  • EndNote: 6
Views and downloads (calculated since 04 Jun 2020)
Cumulative views and downloads (calculated since 04 Jun 2020)

Viewed (geographical distribution)

Total article views: 314 (including HTML, PDF, and XML) Thereof 314 with geography defined and 0 with unknown origin.
Country # Views %
  • 1



No saved metrics found.


No discussed metrics found.
Latest update: 11 Aug 2020
Publications Copernicus
Short summary
Occurrences, size distributions, and number fractions of individual aerosol particles from the Amazon basin during the GoAmazon2014/5 campaign were analyzed using transmission electron microscopy. Aerosol particles from natural sources (e.g., mineral dust, primary biological aerosols, and sea salts) during the wet season originated from the Amazon forest and long-range transports (the Saharan desert and the Atlantic Ocean). They commonly mix at an individual particle scale during transport.
Occurrences, size distributions, and number fractions of individual aerosol particles from the...