The Effect of Continental Air Mass on the Modification of Individual Sea-Salt Particles Collected over the Coast and the Open Sea

Miura, Kazuhiko; Kumakura, Toshiro; Sekikawa, Toshio

doi:10.2151/jmsj1965.69.4_429

Cited by 19 publications

(14 citation statements)

References 23 publications

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“…Table 2 shows the result; sea-salt particles with C1/Na < 1 constitute only a small tYaction of the total aerosol particles, ranging from 2 to 20 % in the radius range of 0.14-0.50 gm. This result presents a striking contrast to that obtained for coastal atmospheres, where a large fraction of sea-salt aerosol is modified significantly by anthropogenic SO2 and/or NOx [Parungo et al, 1987;Miura et al, 1991].…”

Section: Although We Have Collected Sulfate Particlescontrasting

confidence: 76%

Shattering and modification of sea‐salt particles in the marine atmosphere

Mouri¹,

Okada²

1993

Geophysical Research Letters

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Sampling of sea‐salt particles was carried out over the western Pacific Ocean. The collected particles were studied individually by X‐ray spectrometry. Sea‐salt particles with radii r ≥ 0.5 μm show a considerable range in their weight ratios of S/Na and Ca/Na, while Cl/Na ratios remain constant at the seawater value. Moreover, there is a tight correlation between S/Na and Ca/Na. This property is attributable to fractionary recrystallization within evaporating drops. Particles with r < 0.5 μm exhibit a similar trend. However, these particles tend to show smaller Cl/Na ratios and larger S/Na ratios than those with r ≥ 0.5 μm. Chemical reaction between sea salt and acidic material, where Cl− is replaced by (SO4)2− and (NO3)−, is the most plausible explanation.

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Section: Although We Have Collected Sulfate Particlescontrasting

confidence: 76%

Shattering and modification of sea‐salt particles in the marine atmosphere

Mouri¹,

Okada²

1993

Geophysical Research Letters

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“…As mentioned above, the vertical features noted in the present study are observed largely in fine sea-salt particles owing to large losses of coarse sea-salt particles during the sampling. Other field measurements in the marine boundary layer (Miura et al, 1991;McInnes et al, 1994;Mouri et al, 1997) also revealed higher Cl − liberation from sea-salt particles (lower Cl/Na) in finer sea-salt particles. Some investigators (Miura et al, 1991;McInnes et al, 1994;Mouri et al, 1997) described the contribution of longer residence time and larger surface area relative to particle volume to fine sea-salt modification.…”

Section: Vertical Features Of Sea-salt Modification Withmentioning

confidence: 79%

“…Other field measurements in the marine boundary layer (Miura et al, 1991;McInnes et al, 1994;Mouri et al, 1997) also revealed higher Cl − liberation from sea-salt particles (lower Cl/Na) in finer sea-salt particles. Some investigators (Miura et al, 1991;McInnes et al, 1994;Mouri et al, 1997) described the contribution of longer residence time and larger surface area relative to particle volume to fine sea-salt modification. Recent laboratory measurements by Caffrey et al (2001) suggested an important contribution of cloud processes to halogen depletion in sea-salt particles.…”

Section: Vertical Features Of Sea-salt Modification Withmentioning

confidence: 79%

“…5), which probably have strong acidic states through the heterogeneous formation of H 2 SO 4 and acidic SO 4 2− . According to Fridlind and Jacobson (2000), uptake of gaseous HCl from sea‐salt modification can strongly effect pH in coarse sea‐salt particles, which are less modified and Cl‐depleted (Miura et al, 1991; McInnes et al, 1994; Mouri et al, 1997; Katoshevski et al, 1999). Therefore, a vertical gradient of sea‐salt modification might also enhance sea‐salt modification in less modified sea‐salt particles in coarse mode through pH decreasing by HCl uptake.…”

Section: Resultsmentioning

confidence: 99%

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

Hara

Osada

Nishita³

et al. 2002

Tellus B

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Airborne and ground‐based aerosol/gas measurements were carried out in Svalbard between mid‐March and mid‐April 2000. From the viewpoint of vertical features of sea‐salt modification in the lower troposphere (≤1500 m) of the Arctic spring, more than 1000 individual sea‐salt particles were analyzed with scanning electron microscopy energy dispersive X‐ray spectrometry (SEM‐EDX) in the present study. Individual particle analysis suggested a vertical gradient of sea‐salt modification in fine sea‐salt particles with an altitude of 59–1485 m above sea level (asl), e.g. chlorine liberation rates of 33.0% (212 m asl) and 81.0% (1266 m asl) on 15 March, and 72.7% (100 m asl), 83.8% (495 m asl) and 95.8% (1411 m asl) on 26 March. Sea salts may be dominantly modified with SO2 and SO42− under Arctic haze conditions with higher SO2 concentration (≥2 nmol m−3), whereas they are dominantly modified with NO3− and reactive nitrogen oxides under Arctic background conditions, with [HNO3] of 0.15–1.3 nmol m−3 and [SO2] of 0.04–2 nmol m−3. Vertical trends in sea‐salt modification suggested that it makes a significant contribution to the formation of reactive halogen species in the upper boundary layer and the lower free troposphere of the spring Arctic.

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“…As sea breeze becomes stronger, more soil and sea-salt particles, which have relatively larger size, might be generated. At the same time, the polluted air must be swept away inland.To obtain more solid evidence of the effect of sea-salt and soil particles on the observed high 8t events, we need a more direct analytical method, e.g., collection of the suspended aerosols by a cascade impactor and the morphological and multielement analysis with scanning electron microscope (SEM) and energy dispersive X ray (EDX) analyses [e.g.,Miura et al, 1991].…”

mentioning

confidence: 99%

Application of lidar depolarization measurement in the atmospheric boundary layer: Effects of dust and sea‐salt particles

Murayama¹,

Okamoto²,

Kaneyasu³

et al. 1999

J. Geophys. Res.

Self Cite

173

127

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Abstract. We intensively observed the atmospheric boundary layer with a polarization lidar, a Sun photometer, and a high-volume sampler at a coastal area of Tokyo Bay. The purpose of the observation is to investigate a phenomenon discovered in the past summer: relatively high depolarization ratio events (•10% at peak) in the lower atmosphere associated with sea breeze. From the chemical analyses of the simultaneously sampled aerosols, we found that the depolarization ratio might be related to crystallized sea salt and dust particles. A boundary structure was clearly revealed by the depolarization ratio in the lower atmosphere, which might correspond to the mixed layer (the internal boundary layer) or the sea breeze in which crystallized sea salt and/or dust particles were diffused. We also presented the first numerical calculation on the depolarization ratio of the cubic particles to apply crystallized sea-salt (NaC1) particles by the dipole discrete approximation (DDA) method: the calculation yields 8-22% of depolarization ratio for the effective size larger than 0.8 •m at the investigated wavelength (532 nm). IntroductionWe have routinely observed the troposphere, mainly to study the atmospheric boundary layer (ABL) (also referred as the planetary boundary layer (PBL)), with a lidar at Tokyo University of Mercantile Marine (TUMM) (35ø40'N, 139ø47'E) since 1993. Our observation site is located in the center of Tokyo and close to Tokyo Bay, as shown in Figure 1. A large amount of aerosols is locally emitted from anthropogenic origins and greatly affects the local air quality and visibility. This site is suited for the study of the urban atmospheric boundary layer, the boundary layer aerosols, the air pollution meteorology, and the sea-land breeze circulation. Aerosols in ABL, except in spring when Asian dust exists, normally dominate the optical thickness of the atmosphere in this area. Therefore the optical property of the aerosols in the urban ABL is one of the most important targets to estimate the direct and indirect effects of the tropospheric aerosols on the radiation budget.The lidar depolarization technique has been extensively applied to cloud research, e.g., to discriminate the phase of clouds (i.e., water or ice clouds) [Sassen, 1991[Sassen, , 1999. However, the application of this technique to the tropospheric aerosol is relatively rare [Sassen, 1999]. We explored the importance of the lidar depolarization technique in the boundary layer me- teorology and characterization of boundary layer aerosols. One of the advantages of the boundary layer study is that we can relate lidar data to meteorological data and in situ measurements of aerosols at the ground level, although the boundary layer aerosols are mixed with various kinds of aerosols and therefore complex. For the upper atmosphere case we need radiosonde observations and airborne sampling of aerosols for a direct comparison with lidar data, which would be highly expensive.In this paper we define the directly observed total depolarization ratio as...

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The Effect of Continental Air Mass on the Modification of Individual Sea-Salt Particles Collected over the Coast and the Open Sea

Cited by 19 publications

References 23 publications

Shattering and modification of sea‐salt particles in the marine atmosphere

Shattering and modification of sea‐salt particles in the marine atmosphere

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

Application of lidar depolarization measurement in the atmospheric boundary layer: Effects of dust and sea‐salt particles

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