Extremely high proportions of soot particles in the upper troposphere over Japan

Okada, Kikuo; Ikegami, Machiko; Uchino, Osamu; Nikaidou, Yoshinobu; Zaizen, Yuji; Tsutsumi, Yukitomo; Makino, Yukio

doi:10.1029/92gl00487

Cited by 22 publications

(8 citation statements)

References 19 publications

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“…No statistically significant difference between the ratios of the EC to PM2.5 for the rainy days and for the no‐rain days was found for P = 0.05. This suggests that the particulate EC would be strongly associated with hygroscopic species in the fine aerosols over this area, which has been also suggested by past studies [e.g., Okada et al , 1992].…”

Section: Resultssupporting

confidence: 84%

“…Soot particles consist of EC that is the principal light‐absorbing species in atmospheric aerosols [ Seinfeld and Pandis , 1998]. Furthermore, soot particles frequently adsorb hydrophilic materials [ Okada et al , 1992] and are incorporated into cloud droplets, which reduces the cloud albedo [ Kaufman and Nakajima , 1993]. In spite of their importance to aerosol radiative properties, annual observations of particulate carbon have been rarely reported over the east Asian Pacific rim compared to ionic and mineral species.…”

Section: Introductionmentioning

confidence: 99%

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Regional climatology of particulate carbonaceous substances in the northern area of the east Asian Pacific rim

et al. 2007

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A year‐round observation of atmospheric aerosols and their associated species was conducted from March 2001 to May 2002 on Rishiri Island in the northern area of the east Asian Pacific rim region. Asian outflows brought continental air masses to this area during the period from the autumn to the spring although marine air masses from the high‐latitudinal ocean often broke into this area during the midwinter. In contrast, marine air masses were predominant over this area in the summer. Particulate elemental carbon (EC) would be mainly transported with biomass smoke particles, and seasonal variation in its concentrations was well correlated with the air mass alternation, showing higher concentrations during the period from the autumn to the spring with some decreases in the midwinter. The concentrations of particulate organic carbon (OC) showed a similar seasonal trend with those of the particulate EC, but relatively high concentrations were found in the summer due to photochemical secondary productions. The particulate OC that is vaporized by heating at higher temperatures (OCHT) would be mainly carried with the biomass smoke, and the particulate OC that is vaporized at lower temperatures (OCLT) would be mainly caused by secondary production processes. Summer enhancements of the secondary species, such as OC and nss‐SO42–, caused decreases in the ratio of EC/PM2.5, which would contribute to the high single scattering albedo of fine aerosols in the summer. Aerosols in the Asian outflows in this area are relatively “black” in the winter, although the aerosol mass loading increases in the spring.

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Section: Resultssupporting

confidence: 84%

Section: Introductionmentioning

confidence: 99%

Regional climatology of particulate carbonaceous substances in the northern area of the east Asian Pacific rim

et al. 2007

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“…Whereas elemental C is thought to only occur in soot (or black carbon, BC), organic compounds may occur in any smoke particles, including soot. Single‐particle studies have been scarce on biomass smoke particles, and so little information is available on the individual‐particle level [ Gaudichet et al , 1995; Liu et al , 2000; Okada et al , 2001; Ikegami et al , 2001] or on carbonaceous aerosols in general [ Katrinak et al , 1992, 1993; Sheridan , 1989; Okada et al , 1992; Pósfai et al , 1999]. Since carbonaceous particles are the least accessible among the major types of tropospheric aerosol particles for single‐particle electron‐beam methods, the lack of data is understandable.…”

Section: Introductionmentioning

confidence: 99%

Individual aerosol particles from biomass burning in southern Africa: 1. Compositions and size distributions of carbonaceous particles

et al. 2003

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[1] Individual aerosol particles in smoke plumes from biomass fires and in regional hazes in southern Africa were studied using analytical transmission electron microscopy (TEM), which allowed detailed characterization of carbonaceous particle types in smoke and determination of changes in particle properties and concentrations during smoke aging. Based on composition, morphology, and microstructure, three distinct types of carbonaceous particles were present in the smoke: organic particles with inorganic (K-salt) inclusions, ''tar ball'' particles, and soot. The relative number concentrations of organic particles were largest in young smoke, whereas tar balls were dominant in a slightly aged ($1 hour) smoke from a smoldering fire. Flaming fires emitted relatively more soot particles than smoldering fires, but soot was a minor constituent of all studied plumes. Further aging caused the accumulation of sulfate on organic and soot particles, as indicated by the large number of internally mixed organic/sulfate and soot/sulfate particles in the regional haze. Externally mixed ammonium sulfate particles dominated in the boundary layer hazes, whereas organic/sulfate particles were the most abundant type in the upper hazes. Apparently, elevated haze layers were more strongly affected by biomass smoke than those within the boundary layer. Based on size distributions and the observed patterns of internal mixing, we hypothesize that organic and soot particles are the cloudnucleating constituents of biomass smoke aerosols. Sea-salt particles dominated in the samples taken in stratus clouds over the Atlantic Ocean, off the coast of Namibia, whereas a distinct haze layer above the clouds consisted of aged biomass smoke particles.

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“…There exist several observational reports of presence of BC at upper tropospheric and the stratospheric altitudes (Chuan and Woods, 1984;Okada et al, 1992;Pusechel et al, 1992;Sheridan et al, 1994;Blake and Kato, 1995;Pueschel et al, 1997;Strawa et al, 1999;Baumgardner et al, 2004;Schwarz et al, 2006;Kremser et al, 2016). One of the ways to ascertain the occurrence of such layers in the stratosphere is to examine the CALIOP LIDAR (on board CALIPSO satellite) extinction coefficient data (at 550 nm).…”

Section: Occurrence Of Bc At High Altitudes: Observational Evidencementioning

confidence: 99%

Possible climatic implications of high altitude emissions of black carbon

Govardhan

Satheesh

Nanjundiah

et al. 2017

Preprint

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<p><strong>Abstract.</strong> On account of its strong absorption of solar and terrestrial radiations, Black Carbon (BC) aerosol is known to impact large scale systems such as the Asian monsoon, Himalayan glaciers etc, besides affecting the thermal structure of lower atmosphere. While most studies focus on the near-surface abundance and impacts of BC, our study, using online regional chemistry transport model (WRF-Chem) simulations, examines the implications of sharp and confined layers of high BC concentration (called <q>elevated BC layers</q>) at altitudes of about 4.5&#8201;km and 8&#8201;km over the Indian region, as revealed in the recent in-situ measurements using high-altitude balloons. Our study demonstrates, that emissions from high-flying aircrafts are the most likely cause of these elevated BC layers. Furthermore, we show that such aircraft-emitted BC can get transported to even upper tropospheric/lower stratospheric heights (~&#8201;17&#8201;km) aided by the strong monsoonal convection occurring over the region, which are known to overshoot the tropical tropopause leading to injection of tropospheric air mass (along with its constituent aerosols) into the stratosphere. We show observational evidence for such an intrusion of tropospheric BC into the stratosphere over Indian region, using extinction coefficient and particle depolarization ratio data from CALIOP Lidar on-board the CALIPSO satellite. We hypothesise that such intrusions of BC to lower stratosphere and its consequent longer residence time in the stratosphere would have significant implications for stratospheric ozone, considering the already reported ozone depleting potential of BC.</p>

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Extremely high proportions of soot particles in the upper troposphere over Japan

Cited by 22 publications

References 19 publications

Regional climatology of particulate carbonaceous substances in the northern area of the east Asian Pacific rim

Regional climatology of particulate carbonaceous substances in the northern area of the east Asian Pacific rim

Individual aerosol particles from biomass burning in southern Africa: 1. Compositions and size distributions of carbonaceous particles

Possible climatic implications of high altitude emissions of black carbon

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