Next Article in Journal
IEQ Field Investigation in High-Performance, Urban Elementary Schools
Previous Article in Journal
Characterization of Urban New Particle Formation in Amman—Jordan
Open AccessArticle

Internal Structure of Asian Dust Particles over the Western North Pacific: Analyses Using Focused Ion Beam and Transmission Electron Microscopy

1
Environmental Study of Nagoya University, Nagoya University, Nagoya 464-8601, Japan
2
Faculty of Science, Tokyo University of Science, Tokyo 162-8601, Japan
3
Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba 277-8564, Japan
4
Tokyo Metropolitan Government, Tokyo 163-8001, Japan
5
The Center for Scientific Instrument Renovation and Manufacturing Support, Osaka University, Osaka 565-0871, Japan
6
Center for Environmental Science in Saitama, Saitama 347-0115, Japan
*
Author to whom correspondence should be addressed.
Atmosphere 2020, 11(1), 78; https://doi.org/10.3390/atmos11010078
Received: 28 October 2019 / Revised: 25 December 2019 / Accepted: 31 December 2019 / Published: 9 January 2020
(This article belongs to the Section Aerosols)
Mineral dust aerosols, which comprise multiple mineral species, are transported far from their source desert areas to the open ocean. After an Asian dust outflow event was observed over a marine boundary layer in the western North Pacific on February 29, 2012 on research vessel (R/V) Hakuho Maru, two dust particles of about 6 μm diameter were analyzed. First, they were sliced by using a focused ion beam (FIB). Their mineralogical structures and the elemental distribution of their cross-sections were subsequently analyzed with the use of transmission electron microscopy (TEM) and energy-dispersive X ray spectrometry (EDS). These analyses revealed that the dust particles consisted mainly of calcite and silica. Furthermore, Fe-containing domains were found in the submicrometer area surrounded by calcite and silica. A sulfur-containing domain that co-exists with calcium was found in a small domain near the particle surface, but no clear sign of atmospheric aging was found in most of the calcite domain. The inhomogeneous particle structure implies that the dissolution of iron and calcite in dust particles after ocean deposition depends on the physical structures of particles and their degree of aging according to atmospheric conditions during transport. Those factors must be adequately treated when estimating Asian dust effects on marine primary production. View Full-Text
Keywords: aerosol iron; aerosol solubility; Asian dust; atmospheric aging; electron micrograph; FIB; mineral dust; mineralogical structure aerosol iron; aerosol solubility; Asian dust; atmospheric aging; electron micrograph; FIB; mineral dust; mineralogical structure
Show Figures

Figure 1

MDPI and ACS Style

Ueda, S.; Miki, Y.; Kato, H.; Miura, K.; Nakayama, H.; Furutani, H.; Uematsu, M. Internal Structure of Asian Dust Particles over the Western North Pacific: Analyses Using Focused Ion Beam and Transmission Electron Microscopy. Atmosphere 2020, 11, 78.

Show more citation formats Show less citations formats
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

1
Back to TopTop