scholarly journals Measurement report: Molecular composition, optical properties, and radiative effects of water-soluble organic carbon in snowpack samples from northern Xinjiang, China

2021 ◽  
Vol 21 (11) ◽  
pp. 8531-8555
Author(s):  
Yue Zhou ◽  
Christopher P. West ◽  
Anusha P. S. Hettiyadura ◽  
Xiaoying Niu ◽  
Hui Wen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Radiative Forcing ◽  
Molecular Level ◽  
Bulk Composition ◽  
Water Soluble ◽  
Northern Xinjiang ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

Abstract. Water-soluble organic carbon (WSOC) in the cryosphere has an important impact on the biogeochemistry cycling and snow–ice surface energy balance through changes in the surface albedo. This work reports on the chemical characterization of WSOC in 28 representative snowpack samples collected across a regional area of northern Xinjiang, northwestern China. We employed multimodal analytical chemistry techniques to investigate both bulk and molecular-level composition of WSOC and its optical properties, informing the follow-up radiative forcing (RF) modeling estimates. Based on the geographic differences and proximity of emission sources, the snowpack collection sites were grouped as urban/industrial (U), rural/remote (R), and soil-influenced (S) sites, for which average WSOC total mass loadings were measured as 1968 ± 953 ng g−1 (U), 885 ± 328 ng g−1 (R), and 2082 ± 1438 ng g−1 (S), respectively. The S sites showed the higher mass absorption coefficients at 365 nm (MAC365) of 0.94 ± 0.31 m2 g−1 compared to those of U and R sites (0.39 ± 0.11 m2 g−1 and 0.38 ± 0.12 m2 g−1, respectively). Bulk composition of WSOC in the snowpack samples and its basic source apportionment was inferred from the excitation–emission matrices and the parallel factor analysis featuring relative contributions of one protein-like (PRLIS) and two humic-like (HULIS-1 and HULIS-2) components with ratios specific to each of the S, U, and R sites. Additionally, a sample from site 120 showed unique pollutant concentrations and spectroscopic features remarkably different from all other U, R, and S samples. Molecular-level characterization of WSOC using high-resolution mass spectrometry (HRMS) provided further insights into chemical differences among four types of samples (U, R, S, and 120). Specifically, many reduced-sulfur-containing species with high degrees of unsaturation and aromaticity were uniquely identified in U samples, suggesting an anthropogenic source. Aliphatic/protein-like species showed the highest contribution in R samples, indicating their biogenic origin. The WSOC components from S samples showed high oxygenation and saturation levels. A few unique CHON and CHONS compounds with high unsaturation degree and molecular weight were detected in the 120 sample, which might be anthraquinone derivatives from plant debris. Modeling of the WSOC-induced RF values showed warming effects of 0.04 to 0.59 W m−2 among different groups of sites, which contribute up to 16 % of that caused by black carbon (BC), demonstrating the important influences of WSOC on the snow energy budget.

scholarly journals Measurement report: Molecular composition, optical properties, and radiative effects of water-soluble organic carbon in snowpack samples from Northern Xinjiang, China

2021 ◽  
Author(s):  
Yue Zhou ◽  
Christopher P. West ◽  
Anusha P. S. Hettiyadura ◽  
Xiaoying Niu ◽  
Hui Wen ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Radiative Forcing ◽  
Molecular Level ◽  
Bulk Composition ◽  
Water Soluble ◽  
Northern Xinjiang ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

Abstract. Water-soluble organic carbon (WSOC) in the cryosphere has important impact on the biogeochemistry cycling and snow/ice surface energy balance through changes in the surface albedo. This work reports on chemical characterization of WSOC in 28 representative snowpack samples collected across regional area of northern Xinjiang, northwestern China. We employed multi-modal analytical chemistry techniques to investigate both bulk and molecular-level composition of WSOC and its optical properties, informing the follow-up radiative forcing (RF) modeling estimates. Based on the geographic differences and proximity of emission sources, the snowpack collection sites were grouped as urban/industrial (U), rural/remote (R), and soil-influenced (S) sites, for which average WSOC total mass loadings were measured as 1968 ± 953 ng g−1 (U), 885 ± 328 ng g−1 (R), and 2082 ± 1438 ng g−1 (S), respectively. The S sites showed the higher mass absorption coefficients at 365 nm (MAC365) of 0.94 ± 0.31 m2 g−1 compared to those of U and R sites (0.39 ± 0.11 m2 g−1 and 0.38 ± 0.12 m2 g−1, respectively). Bulk composition of WSOC in the snowpack samples and its basic source apportionment was inferred from the Excitation-Emission Matrices and the Parallel Factor analysis featuring relative contributions of two humic-like (HULIS-1 and HULIS-2) and one protein-like (PRLIS) components with ratios specific to each of the S, U, and R sites. Additionally, a sample from site 120 showed unique pollutant concentrations and spectroscopic features remarkably different from all other U, R, and S samples. Molecular-level characterization of WSOC using high-resolution mass spectrometry (HRMS) provided further insights into chemical differences among four types of samples (U, R, S, and 120). Specifically, much more reduced S-containing species with high degree of unsaturation and aromaticity were uniquely identified in U samples, suggesting an anthropogenic source. Aliphatic/proteins-like species showed highest contribution in R samples, indicating their biogenic origin. The WSOC components from S samples showed high oxygenation and saturation levels. A few of unique CHON and CHONS compounds with high molecular weight were detected in the 120 sample, which might be anthraquinone derivatives from plant debris. Modeling of the WSOC-induced RF values showed warming effects of 0.04 to 0.59 W m−2 among different groups of sites, which contribute up to 16 % of that caused by BC, demonstrating the important influences of WSOC on the snow energy budget.

scholarly journals Water-soluble organic carbon aerosols during a full New Delhi winter: Isotope-based source apportionment and optical properties

2014 ◽  
Vol 119 (6) ◽  
pp. 3476-3485 ◽  
Author(s):  
Elena N. Kirillova ◽  
August Andersson ◽  
Suresh Tiwari ◽  
Atul Kumar Srivastava ◽  
Deewan Singh Bisht ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Source Apportionment ◽  
Water Soluble ◽  
New Delhi ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon ◽  
Carbon Aerosols

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

2017 ◽  
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.

scholarly journals Estimation of Source-Based Aerosol Optical Properties for Polydisperse Aerosols from Receptor Models

2019 ◽  
Vol 9 (7) ◽  
pp. 1443 ◽  
Author(s):  
Chang Jung ◽  
Ji Lee ◽  
Junshik Um ◽  
Seoung Lee ◽  
Young Yoon ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Mass Concentration ◽  
Water Soluble ◽  
Aerosol Size Distribution ◽  
Receptor Model ◽  
Aerosol Optical Properties ◽  
Extinction Coefficients ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

We estimated source-based aerosol optical properties for polydisperse aerosols according to a chemical-species-resolved mass contribution method based on source apportionment. We investigated the sensitivity of aerosol optical properties based on PM2.5 (particulate matter that have a diameter of less than 2.5 micrometers) monitoring results. These aerosols were composed of ions, metals, elemental carbon, and water-soluble organic carbon which includes humic-like carbon substances and water-soluble organic carbon. We calculated aerosols’ extinction coefficients based on the PM2.5 composition data and the results of a multivariate receptor model (Solver for Mixture Problem model, SMP). Based on the mass concentration of chemical composition and nine sources calculated with the SMP receptor model, we estimated the size-resolved mass extinction efficiencies for each aerosol source using a multilinear regression model. Consequently, this study quantitatively determined the size resolved sources contributing to the apportionment-based aerosol optical properties and calculated their respective contributions. The results show that source-resolved mass concentrations and extinction coefficients had varying contributions. This discrepancy between the source-based mass concentration and extinction coefficient was mainly due to differences between the source-dependent aerosol size distribution and the aerosol optical properties from different sources.

scholarly journals Sources and light absorption of water-soluble organic carbon aerosols in the outflow from northern China

2014 ◽  
Vol 14 (3) ◽  
pp. 1413-1422 ◽  
Author(s):  
E. N. Kirillova ◽  
A. Andersson ◽  
J. Han ◽  
M. Lee ◽  
Ö. Gustafsson
Keyword(s):  
Organic Carbon ◽  
Light Absorption ◽  
Radiative Forcing ◽  
Large Fraction ◽  
Northern China ◽  
Water Soluble ◽  
Cloud Formation ◽  
Carbonaceous Aerosols ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

Abstract. High loadings of anthropogenic carbonaceous aerosols in Chinese air influence the air quality for over one billion people and impact the regional climate. A large fraction (17–80%) of this aerosol carbon is water-soluble, promoting cloud formation and thus climate cooling. Recent findings, however, suggest that water-soluble carbonaceous aerosols also absorb sunlight, bringing additional direct and indirect climate warming effects, yet the extent and nature of light absorption by this water-soluble "brown carbon" and its relation to sources is poorly understood. Here, we combine source estimates constrained by dual carbon isotopes with light-absorption measurements of water-soluble organic carbon (WSOC) for a March 2011 campaign at the Korea Climate Observatory at Gosan (KCOG), a receptor station in SE Yellow Sea for the outflow from northern China. The mass absorption cross section at 365 nm (MAC365) of WSOC for air masses from N. China were in general higher (0.8–1.1 m2 g−1), than from other source regions (0.3–0.8 m2 g−1). However, this effect corresponds to only 2–10% of the radiative forcing caused by light absorption by elemental carbon. Radiocarbon constraints show that the WSOC in Chinese outflow had significantly higher fraction fossil sources (30–50%) compared to previous findings in S. Asia, N. America and Europe. Stable carbon (δ13C) measurements were consistent with aging during long-range air mass transport for this large fraction of carbonaceous aerosols.

scholarly journals Investigating the evolution of water-soluble organic carbon in evaporating cloud water

2021 ◽  
Author(s):  
Vikram Pratap ◽  
Amy E. Christiansen ◽  
Annmarie G. Carlton ◽  
Sara Lance ◽  
Paul Casson ◽  
...  
Keyword(s):  
Optical Properties ◽  
Organic Carbon ◽  
Cloud Water ◽  
Atmospheric Particles ◽  
Water Soluble ◽  
Secondary Aerosol ◽  
Aerosol Mass ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon

Cloud cycling plays a key role in the evolution of atmospheric particles and gases, producing secondary aerosol mass and transforming the optical properties and impacts of aerosols globally.

Chemical Characterization of Water-Soluble Organic Aerosols at Jeju Island Collected During ACE-Asia

2004 ◽  
Vol 1 (1) ◽  
pp. 13 ◽  
Author(s):  
Hong Yang ◽  
Jinhui Xu ◽  
Wai-Shing Wu ◽  
Chun Hong Wan ◽  
Jian Zhen Yu
Keyword(s):  
Organic Carbon ◽  
South Korea ◽  
Chemical Characterization ◽  
Water Soluble ◽  
Asia Pacific ◽  
Carbon Mass ◽  
Water Soluble Organic Carbon ◽  
Soluble Organic Carbon ◽  
Aerosol Characterization

Environmental Context. Atmospheric aerosols — particles suspended in the atmosphere — are responsible for many phenomena, including formation of cloud condensation nuclei and degradation of regional visibility. Water-soluble organic carbon (WSOC) components make up a significant fraction of the aerosols' carbon mass, and have consequently received increasing attention from researchers. The chemical composition of the WSOC fraction, and thus their sources and effects, are not well known. This study focusses on WSOC from samples collected in South Korea as part of ACE-Asia (Asia-Pacific Regional Aerosol Characterization Experiment), a large international collaboration including Asia, the USA, Europe and Australia. Abstract.During the Asia-Pacific Regional Aerosol Characterization Experiment (ACE-Asia) intensive field campaign, aerosol samples of less than 2.5 μm diameter were collected at Jeju Island, South Korea, for chemical characterization of the water-soluble organic carbon (WSOC) fraction. The WSOC fraction had an average mass concentration of roughly half of that of sulfate and accounted for about two-thirds of the organic carbon mass. Thirty individual water-soluble organic compounds, belonging to the classes of mono- and di-carboxylic acids, aliphatic amines, and amino acids, were identified, accounting for 14% of the WSOC on a carbon basis. Oxalic acid was the most abundant single component. An additional 3% of the WSOC was estimated to be monomeric carbohydrates. Thermal analysis of the aerosol’s water extracts indicated that a significant fraction (~50%) of WSOC was thermally recalcitrant, possibly consisting of polymeric materials.

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