Vertical variations of sea-salt modification in the boundary layer of
                        spring Arctic during the ASTAR 2000 campaign

Hara, Keiichiro; Osada, Kazuo; Nishita, Chiharu; Yamagata, Sadamu; Yamanocuhi, T.; Herber, Andreas; Matsunaga, Katsuji; Iwasaka, Yasunobu; Nagatani, Masahiro; Nakata, Hisao

doi:10.3402/tellusb.v54i4.16671

Cited by 15 publications

(16 citation statements)

References 29 publications

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“…for estimating the aerosol mass mixing ratio). The main results of the entire airborne impactor measurements have already been discussed in detail in Hara et al (2002Hara et al ( , 2003. The findings for 23 and 26 March are as follows: the main components were sulfate, soot and sea salt particles; smaller components include a small number of mineral dust particles.…”

Section: Vertical Profile From Airborne Observationsmentioning

confidence: 76%

Arctic Study of Tropospheric Aerosol and Radiation (ASTAR) 2000: Arctic haze case study

Yamanouchi

Treffeisen

Herber

et al. 2005

Tellus B: Chemical and Physical Meteorology

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A strong haze event occurred between 21 and 25 March in which the optical depth from ground-based observation was 0.18, which was significantly greater than the background value of 0.06. Airborne measurements on 23 March during this haze event showed a high aerosol layer with an extinction coefficient of 0.03 km −1 or more up to 3 km and a scattering coefficient from 0.02 in the same altitude range. From the chemical analyses of airborne measurements, sulfate, soot and sea salt particles were dominant, and there was a high mixing ratio of external soot particles in some layers during the haze event, whereas internal mixing of soot in sulfate was noticeable in some layers for the background condition. We argue that the high aerosol loading is due to direct transport from anthropogenic source regions. In this paper we focus on the course of the haze event in detail through analyses of the airborne and ground-based results.

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Section: Vertical Profile From Airborne Observationsmentioning

confidence: 76%

Arctic Study of Tropospheric Aerosol and Radiation (ASTAR) 2000: Arctic haze case study

Yamanouchi

Treffeisen

Herber

et al. 2005

Tellus B: Chemical and Physical Meteorology

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“…Thus, modification of sea salt particles may change their size, light scattering properties and affinity for CCN formation. The presence of water on sea salt surfaces also greatly enhances their reactivity with gases compared with dry sea salt (ten Brink, 1998;Hara et al, 2002). Furthermore, the nitrate and the non-sea salt SO rapidly from the atmosphere due to the large sizes of particles, which reduces the amounts of scavenged species in the atmosphere.…”

Section: Silicates and Metal Oxides/hydroxidesmentioning

confidence: 99%

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Niemi

Saarikoski

Tervahattu³

et al. 2006

Atmos. Chem. Phys.

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Abstract.Aerosol samples were collected at a rural background site in southern Finland in May 2004 during pollution episode (PM 1 ∼16 µg m −3 , backward air mass trajectories from south-east), intermediate period (PM 1 ∼5 µg m −3 , backtrajectories from north-east) and clean period (PM 1 ∼2 µg m −3 , backtrajectories from northwest/north). The elemental composition, morphology and mixing state of individual aerosol particles in three size fractions were studied using transmission electron microscopy (TEM) coupled with energy dispersive X-ray (EDX) microanalyses. The TEM/EDX results were complemented with the size-segregated bulk chemical measurements of selected ions and organic and elemental carbon. Many of the particles in PM 0.2−1 and PM 1−3.3 size fractions were strongly internally mixed with S, C and/or N. The major particle types in PM 0.2−1 samples were 1) soot and 2) (ammonium)sulphates and their mixtures with variable amounts of C, K, soot and/or other inclusions. Number proportions of those two particle groups in PM 0.2−1 samples were 0-12% and 83-97%, respectively. During the pollution episode, the proportion of Ca-rich particles was very high (26-48%) in the PM 1−3.3 and PM 3.3−11 samples, while the PM 0.2−1 and PM 1−3.3 samples contained elevated proportions of silicates (22-33%), metal oxides/hydroxides (1-9%) and tar balls (1-4%). These aerosols originated mainly from polluted areas of Eastern Europe, and some open biomass burning smoke was also brought by long-range transport. During the clean period, when air masses arrived from the Arctic Ocean, PM 1−3.3 samples contained mainly sea salt particles (67-89%) with a variable rate of Cl substitution (mainly by NO porous (sponge-like) Na-rich particles (35%) with abundant S, K and O. They might originate from the burning of wood pulp wastes of paper industry. The proportion of biological particles and C-rich fragments (probably also biological origin) were highest in the PM 3.3−11 samples (0-81% and 0-22%, respectively). The origin of different particle types and the effect of aging processes on particle composition and their hygroscopic and optical properties are discussed.

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“…Silicate particles contained elements such as Na, Mg, Al, Si, K, Ca, Ti and Fe, in various combinations, indicating that they are composed of (or mixtures of) quartz, feldspar, mica, amphibole and different clay minerals. Most of the sea salt particles collected in the vicinity of Niamey had lower Cl/Na atomic fractions relative to sea water, which is an indication of aging due to the Cl liberation during transport (Hara et al, 2002).…”

Section: Morphology and Compositionmentioning

confidence: 99%

Cloud processing of mineral dust: direct comparison of cloud residual and clear sky particles during AMMA aircraft campaign in summer 2006

et al. 2010

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Abstract. In order to gain insights into the characteristics of the mineral dust particles incorporated in the actual cloud droplets and the related cloud processing, the French ATR-42 research aircraft equipped both with a counterflow virtual impactor (CVI) and community aerosol inlet was deployed in Niamey, Niger (13 • 30 N, 02 • 05 E) in August 2006 within the framework of the African Monsoon Multidisciplinary Analysis (AMMA) project.Cloud residual and clear-sky particles were collected separately and analyzed individually using a transmission electron microscope (TEM) and a scanning electron microscope coupled with an energy dispersive X-ray spectroscopy (SEM-EDX). The analysis revealed interesting characteristics on the coarse dust particles (Dp>1µm), particularly those which likely had acted as CCN.Traces of heterogeneously formed secondary sulfate, chloride and nitrate were found on many dust particles (though fraction of sulfate may be present in the form of gypsum as primary dust component). These secondary species were particularly enhanced in clouds (i.e. cloud processing). The study illustrates that calcium-rich particles assumed to be carbonates (Calcite, Dolomite) contained the secondary species in significantly larger frequency and amount than the silicates (Quartz, Feldspar, Mica, Clay), suggesting that they represent the most reactive fraction of the mineral dust. A surprisingly large fraction of the Ca-rich particles were already found in deliquesced form even in clear-sky condiCorrespondence to: A. Matsuki (matsuki@staff.kanazawa-u.ac.jp) tions, most probably reflecting their extreme hygroscopicity, resulting from their reaction with HNO 3 gas.Both silicate and Ca-rich particles were found dominant among the supermicron cloud residues, and they were supposed to be those previously activated as CCN. It is highly probable that the observed formation of soluble materials enhanced their cloud nucleating abilities.

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Vertical variations of sea-salt modification in the boundary layer of spring Arctic during the ASTAR 2000 campaign

Cited by 15 publications

References 29 publications

Arctic Study of Tropospheric Aerosol and Radiation (ASTAR) 2000: Arctic haze case study

Arctic Study of Tropospheric Aerosol and Radiation (ASTAR) 2000: Arctic haze case study

Changes in background aerosol composition in Finland during polluted and clean periods studied by TEM/EDX individual particle analysis

Cloud processing of mineral dust: direct comparison of cloud residual and clear sky particles during AMMA aircraft campaign in summer 2006

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