Organic Molecular Tracers in PM2.5 at Urban Sites during Spring and Summer in Japan: Impact of Secondary Organic Aerosols on Water-Soluble Organic Carbon

To understand the characteristics of secondary organic aerosols (SOAs) and estimate their impact on water-soluble organic carbon (WSOC) in urban areas in Japan, we measured 17 organic tracers using gas chromatography–mass spectrometry from particulate matter with an aerodynamic diameter smaller than 2.5 μm collected at five urban sites in Japan during spring and summer. Most anthropogenic, monoterpene-derived, and isoprene-derived SOA tracers showed meaningful correlations with potential ozone in both these seasons. These results indicate that oxidants play an important role in SOAs produced during both seasons in urban cities in Japan. WSOC was significantly affected by anthropogenic and monoterpene-derived SOAs during spring and three SOA groups during summer at most of the sites sampled. The total estimated secondary organic carbons (SOCs), including mono-aromatic, di-aromatic, monoterpene-derived, and isoprene-derived SOCs, could explain the WSOC fractions of 39–63% in spring and 46–54% in summer at each site. Notably, monoterpene-derived and mono-aromatic SOCs accounted for most of the total estimated SOCs in both spring (85–93%) and summer (75–82%) at each site. These results indicate that SOAs significantly impact WSOC concentrations during both these seasons at urban sites in Japan.

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Significant Seasonal Change in Optical Properties by atmospheric humic-like substances (HULIS) in Water-Soluble Organic Carbon Aerosols

10.5194/acp-2017-554 ◽

2017 ◽

Cited By ~ 2

Author(s):

Heejun Han ◽

Guebuem Kim

Keyword(s):

Optical Properties ◽

Organic Carbon ◽

Uv Radiation ◽

Dominant Role ◽

Critical Role ◽

Organic Aerosols ◽

Water Soluble ◽

Photochemical Degradation ◽

Water Soluble Organic Carbon ◽

Soluble Organic Carbon

Abstract. Atmospheric humic-like substance (HULIS) is an important fraction of water-soluble organic carbon (WSOC) accounting for the light-absorbing properties of organic aerosols. HULIS is responsible for light-absorbing properties of organic aerosols in the atmosphere. Although various sources of HULIS have been studied extensively, its sinks are poorly constrained. In this study, we found seasonal changes in the optical and chemical characteristics of HULIS and WSOC, which are decreased by approximately 80 % and 30 %, respectively, from the cold season (Oct–Jan) to the warm season (Jun–Sep) due to enhanced solar ultraviolet (UV) radiation. The dominant role of photochemical degradation on light-absorbing organic aerosols, as a sink of HULIS, was further confirmed based on a laboratory experiment by evaluating impact of UV radiation on the optical properties of HULIS and WSOC contents. Our results suggest that seasonal variation of HULIS in WSOC is resulted mainly by photo-induced degradation in the atmosphere. Thus, photochemical degradation of HULIS seems to play a critical role on seasonal variations in the light-absorbing properties of organic aerosols as well as the biogeochemical impact of WSOC on Earth’s surface.

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WSOC and Its Relationship with BC, Levoglucosan and Transition Metals in the PM2.5 of an Urban Area in the Amazon

Journal of the Brazilian Chemical Society ◽

10.21577/0103-5053.20220011 ◽

2022 ◽

Author(s):

Karenn Fernandes ◽

Erickson dos Santos ◽

Carla Batista ◽

Igor Ribeiro ◽

Victor Piracelli ◽

...

Keyword(s):

Organic Carbon ◽

Transition Metals ◽

Urban Areas ◽

Large Mass ◽

Water Soluble ◽

Linear Coefficient ◽

Strong Linear Correlation ◽

Water Soluble Organic Carbon ◽

Soluble Organic Carbon ◽

The Relationship

Water-soluble organic carbon (WSOC) makes up a large mass fraction of the organic carbon in the aerosol and can influence important cloud processes in the atmosphere. The capacity of WSOC to form metallic complexes with transition metals is well known; however, its influence on the aerosol of urban areas in the Amazon region is not very well known. In this study, we investigated the relationship between WSOC, black carbon (BC), levoglucosan (LEV) and transition metals (Fe, Cu and Mn) present in the PM2.5 (particles with a diameter smaller than 2.5 µm) of an urban environment during the dry season in the central Amazon. Oxalic acid (C2) was used to identify the influence of transition metals on WSOC. The mean mass concentration value of the PM2.5 was 14.72 μg m-3 (2.11-31.68 μg m-3). The WSOC made up 58.34% of the PM2.5 mass, followed by BC (20.28%), and LEV (2.62%). The WSOC showed significant correlation with the transition metals analyzed (> 0.56), especially Mn with C2 (linear coefficient (R2 ) = 0.74). A multiple linear regression with WSOC, BC and LEV showed a strong linear correlation between them (R2 = 0.86), indicating the influence of biomass burning and vehicle traffic on the organic aerosol.

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The effects of isoprene and NOx on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-1171-2018 ◽

2018 ◽

Vol 18 (2) ◽

pp. 1171-1184 ◽

Cited By ~ 10

Author(s):

Marwa M. H. El-Sayed ◽

Diana L. Ortiz-Montalvo ◽

Christopher J. Hennigan

Keyword(s):

Secondary Organic Aerosols ◽

Time Lag ◽

Organic Aerosols ◽

Water Soluble ◽

Oxidation Products ◽

Eastern United States ◽

Water Soluble Organic Carbon ◽

Soluble Organic Carbon ◽

Isoprene Oxidation ◽

Organic Gases

Abstract. Isoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmosphere is highly uncertain. The aim of this study was to characterize the reversibility of aqSOA formed from isoprene at a location in the eastern United States under substantial influence from both anthropogenic and biogenic emissions. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was characterized in Baltimore, Maryland, USA, using measurements of particulate water-soluble organic carbon (WSOCp) in alternating dry and ambient configurations. WSOCp evaporation with drying was observed systematically throughout the late spring and summer, indicating reversible aqSOA formation during these times. We show through time lag analyses that WSOCp concentrations, including the WSOCp that evaporates with drying, peak 6 to 11 h after isoprene concentrations, with maxima at a time lag of 9 h. The absolute reversible aqSOA concentrations, as well as the relative amount of reversible aqSOA, increased with decreasing NOx ∕ isoprene ratios, suggesting that isoprene epoxydiol (IEPOX) or other low-NOx oxidation products may be responsible for these effects. The observed relationships with NOx and isoprene suggest that this process occurs widely in the atmosphere, and is likely more important in other locations characterized by higher isoprene and/or lower NOx levels. This work underscores the importance of accounting for both reversible and irreversible uptake of isoprene oxidation products to aqueous particles.

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Secondary formation of water-soluble organic acids andα-dicarbonyls and their contributions to total carbon and water-soluble organic carbon: Photochemical aging of organic aerosols in the Arctic spring

Journal of Geophysical Research Atmospheres ◽

10.1029/2010jd014299 ◽

2010 ◽

Vol 115 (D21) ◽

Cited By ~ 86

Author(s):

Kimitaka Kawamura ◽

Hideki Kasukabe ◽

Leonard A. Barrie

Keyword(s):

Organic Carbon ◽

Organic Acids ◽

Organic Aerosols ◽

Water Soluble ◽

Total Carbon ◽

The Arctic ◽

Secondary Formation ◽

Water Soluble Organic Carbon ◽

Soluble Organic Carbon ◽

Photochemical Aging

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The effects of isoprene and NOx on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water

10.5194/acp-2017-702 ◽

2017 ◽

Author(s):

Marwa M. H. El-Sayed ◽

Diana L. Ortiz-Montalvo ◽

Christopher J. Hennigan

Keyword(s):

Secondary Organic Aerosols ◽

Time Lag ◽

Organic Aerosols ◽

Water Soluble ◽

Oxidation Products ◽

Eastern United States ◽

Water Soluble Organic Carbon ◽

Soluble Organic Carbon ◽

Isoprene Oxidation ◽

Organic Gases

Abstract. Isoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmosphere is highly uncertain. The aim of this study was to characterize the reversibility of aqSOA formed from isoprene at a location in the eastern United States under substantial influence from both anthropogenic and biogenic emissions. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was characterized in Baltimore, MD using measurements of particulate water-soluble organic carbon (WSOCp) in alternating dry and ambient configurations. WSOCp evaporation with drying was observed systematically throughout the late spring and summer, indicating reversible aqSOA formation during these times. We show through time lag analyses that WSOCp concentrations, including the WSOCp that evaporates with drying, peak ~ 6–11 h after isoprene concentrations, with maxima at a time lag of 9 h. The absolute reversible aqSOA concentrations, as well as the relative amount of reversible aqSOA, increased with decreasing NOx/isoprene ratios, suggesting that isoprene epoxydiol (IEPOX) or other low-NOx oxidation products were responsible for these effects. The observed relationships with NOx and isoprene suggest that this process occurs widely in the atmosphere, and is likely more important in other locations characterized by higher isoprene and/or lower NOx levels. It is also likely that this phenomenon will increase in importance in the future, given predictions of biogenic and anthropogenic emissions under future regulatory and climate scenarios.

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