scholarly journals Effect of biomass burning over the western North Pacific Rim: wintertime maxima of anhydrosugars in ambient aerosols from Okinawa

2014 ◽  
Vol 14 (18) ◽  
pp. 25581-25616 ◽  
Author(s):  
C. Zhu ◽  
K. Kawamura
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
North Pacific ◽  
Western North Pacific ◽  
North China ◽  
Water Soluble ◽  
Pacific Rim ◽  
Chemical Compositions ◽  
Okinawa Island

Abstract. Biomass burning (BB) largely modifies the chemical compositions of atmospheric aerosols on the globe. We collected aerosol samples (TSP) at Cape Hedo, subtropical Okinawa Island from October 2009 to February 2012 to study anhydrosugars as BB tracers. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. We found a clear seasonal trend of levoglucosan and mannosan with winter maxima and summer minima. Positive correlation was found between levoglucosan and nss-K+ (r = 0.38, p < 0.001); the latter is another BB tracer. The analyses of air mass trajectories and fire spots demonstrated that the seasonal variations of anhydrsosugsars are caused by a long-range transport of BB emissions from the Asian continent. We found winter maxima of anhydrosugars, which may be associated with open burning and domestic heating and cooking in north and northeast China, Mongolia and Russia and with the enhanced westerly. The monthly averaged levoglucosan/mannosan ratios were lower (2.1–4.8) in May–June and higher (13.3–13.9) in November–December. The lower values may be associated with softwood burning in north China, Korea and southwest Japan whereas the higher values are probably caused by agriculture waste burning of maize straw in the North China Plain. Anhydrosugars comprised 0.22% of water-soluble organic carbon (WSOC) and 0.13% of organic carbon (OC). The highest values to WSOC (0.37%) and OC (0.25%) were found in winter, again indicating an important BB contribution to Okinawa aerosols in winter. This study provides useful information to better understand the effect of East Asian biomass burning on the air quality in the western North Pacific Rim.

scholarly journals Effect of biomass burning over the western North Pacific Rim: wintertime maxima of anhydrosugars in ambient aerosols from Okinawa

2015 ◽  
Vol 15 (4) ◽  
pp. 1959-1973 ◽  
Author(s):  
C. Zhu ◽  
K. Kawamura ◽  
B. Kunwar
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
North Pacific ◽  
Western North Pacific ◽  
Agricultural Waste ◽  
Northern China ◽  
Water Soluble ◽  
Pacific Rim ◽  
Okinawa Island

Abstract. Biomass burning (BB) largely modifies the chemical composition of atmospheric aerosols on the globe. We collected aerosol samples (TSP) at Cape Hedo, on subtropical Okinawa Island, from October 2009 to February 2012 to study anhydrosugars as BB tracers. Levoglucosan was detected as the dominant anhydrosugar followed by its isomers, mannosan and galactosan. We found a clear seasonal trend of levoglucosan and mannosan with winter maxima and summer minima. Positive correlation was found between levoglucosan and nss-K+ (r = 0.38, p < 0.001); the latter is another BB tracer. The analyses of air mass trajectories and fire spots demonstrated that the seasonal variations of anhydrosugars are caused by long-range transport of BB emissions from the Asian continent. We found winter maxima of anhydrosugars, which may be associated with open burning and domestic heating and cooking in northern and northeastern China, Mongolia and Russia and with the enhanced westerly winds. The monthly averaged levoglucosan / mannosan ratios were lower (2.1–4.8) in May–June and higher (13.3–13.9) in November–December. The lower values may be associated with softwood burning in northern China, Korea and southwestern Japan whereas the higher values are probably caused by agricultural waste burning of maize straw in the North China Plain. Anhydrosugars comprised 0.22% of water-soluble organic carbon (WSOC) and 0.13% of organic carbon (OC). The highest values to WSOC (0.37%) and OC (0.25%) were found in winter, again indicating an important BB contribution to Okinawa aerosols in winter. This study provides useful information to better understand the effect of East Asian biomass burning on the air quality in the western North Pacific Rim.

scholarly journals Dicarboxylic acids, oxoacids, benzoic acid, α-dicarbonyls, WSOC, OC, and ions in spring aerosols from Okinawa Island in the western North Pacific Rim: size distributions and formation processes

2015 ◽  
Vol 15 (18) ◽  
pp. 26509-26554 ◽  
Author(s):  
D. K. Deshmukh ◽  
K. Kawamura ◽  
M. Lazaar ◽  
B. Kunwar ◽  
S. K. R. Boreddy
Keyword(s):  
Organic Carbon ◽  
Benzoic Acid ◽  
North Pacific ◽  
Western North Pacific ◽  
Sea Salt ◽  
Water Soluble ◽  
Pacific Rim ◽  
Size Distributions ◽  
Coarse Mode ◽  
Fine Mode

Abstract. Size-segregated aerosols (9-stages from < 0.43 to > 11.3 μm in diameter) were collected at Cape Hedo, Okinawa in spring 2008 and analyzed for water-soluble diacids (C2–\\C12), ω-oxoacids (ωC2–ωC9), pyruvic acid, benzoic acid and α-dicarbonyls (C2–C3) as well as water-soluble organic carbon (WSOC), organic carbon (OC) and major ions. In all the size-segregated aerosols, oxalic acid (C2) was found as the most abundant species followed by malonic and succinic acids whereas glyoxylic acid (ωC2) was the dominant oxoacid and glyoxal (Gly) was more abundant than methylglyoxal. Diacids (C2–C5), ωC2 and Gly as well as WSOC and OC peaked at 0.65–1.1 μm in fine mode whereas azelaic (C9) and 9-oxononanoic (ωC9) acids peaked at 3.3–4.7 μm in coarse mode. Sulfate and ammonium are enriched in fine mode whereas sodium and chloride are in coarse mode. These results imply that water-soluble species in the marine aerosols could act as cloud condensation nuclei (CCN) to develop the cloud cover over the western North Pacific Rim. The organic species are likely produced by a combination of gas-phase photooxidation, and aerosol-phase or in-cloud processing during long-range transport. The coarse mode peaks of malonic and succinic acids were obtained in the samples with marine air masses, suggesting that they may be associated with the reaction on sea salt particles. Bimodal size distributions of longer-chain diacid (C9) and oxoacid (ωC9) with a major peak in the coarse mode suggest their production by photooxidation of biogenic unsaturated fatty acids via heterogeneous reactions on sea salt particles.

scholarly journals Size distributions of dicarboxylic acids, ketoacids, α-dicarbonyls, sugars, WSOC, OC, EC and inorganic ions in atmospheric particles over Northern Japan: implication for long-range transport of Siberian biomass burning and East Asian polluted aerosols

2010 ◽  
Vol 10 (13) ◽  
pp. 5839-5858 ◽  
Author(s):  
S. Agarwal ◽  
S. G. Aggarwal ◽  
K. Okuzawa ◽  
K. Kawamura
Keyword(s):  
Chemical Composition ◽  
Organic Carbon ◽  
Long Range ◽  
Biomass Burning ◽  
North Pacific ◽  
Western North Pacific ◽  
Source Region ◽  
Inorganic Ions ◽  
Dicarboxylic Acids ◽  
Pacific Rim

Abstract. To better understand the size-segregated chemical composition of aged organic aerosols in the western North Pacific rim, day- and night-time aerosol samples were collected in Sapporo, Japan during summer 2005 using an Andersen impactor sampler with 5 size bins: Dp<1.1, 1.1–2.0, 2.0–3.3, 3.3–7.0, >7.0 μm. Samples were analyzed for the molecular composition of dicarboxylic acids, ketoacids, α-dicarbonyls, and sugars, together with water-soluble organic carbon (WSOC), organic carbon (OC), elemental carbon (EC) and inorganic ions. Based on the analyses of backward trajectories and chemical tracers, we found that during the campaign, air masses arrived from Siberia (a biomass burning source region) on 8–9 August, from China (an anthropogenic source region) on 9–10 August, and from the East China Sea/Sea of Japan (a mixed source receptor region) on 10–11 August. Most of the diacids, ketoacids, dicarbonyls, levoglucosan, WSOC, and inorganic ions (i.e., SO42−, NH4+ and K+) were enriched in fine particles (PM1.1) whereas Ca2+, Mg2+ and Cl− peaked in coarse sizes (>1.1 μm). Interestingly, OC, most sugar compounds and NO3− showed bimodal distributions in fine and coarse modes. In PM1.1, diacids in biomass burning-influenced aerosols transported from Siberia (mean: 252 ng m−3) were more abundant than those in the aerosols originating from China (209 ng m−3) and ocean (142 ng m−3), whereas SO42− concentrations were highest in the aerosols from China (mean: 3970 ng m−3) followed by marine- (2950 ng m−3) and biomass burning-influenced (1980 ng m−3) aerosols. Higher loadings of WSOC (2430 ng m−3) and OC (4360 ng m−3) were found in the fine mode, where biomass-burning products such as levoglucosan are abundant. This paper presents a case study of long-range transported aerosols illustrating that biomass burning episodes in the Siberian region have a significant influence on the chemical composition of carbonaceous aerosols in the western North Pacific rim.

Investigation of atmospheric aerosols over semi-urban and urban areas in Eastern Indo-Gangetic Plain: seasonal variability and source apportionment using PMF

2021 ◽  
Author(s):  
Kanishtha Dubey ◽  
Shubha Verma
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Atmospheric Aerosols ◽  
Urban Areas ◽  
Relative Concentration ◽  
Road Dust ◽  
Water Soluble ◽  
Carbonaceous Aerosols ◽  
Gangetic Plain ◽  
Brick Kilns

&lt;p&gt;The study investigates the chemical composition and source of aerosol origin at a semi-urban (Kharagpur&amp;#8211;Kgp) and urban (Kolkata&amp;#8211;Kol) region during the period February 2015 to January 2016 and September 2010 to August 2011 respectively. Major water-soluble inorganic aerosols (WSII) were determined using Ion chromatography and carbonaceous aerosols (CA) using OC&amp;#8211;EC analyser. A multivariate factor analysis Positive Matrix Factorization (PMF) was used in resolving source of aerosols at the study locations. Seasonal analysis of WSII at Kgp and Kol indicated relative dominance of calcium at both the places followed by sodium, chloride, and magnesium ions. Non-sea salt potassium (nss&amp;#8211;K&lt;sup&gt;+&lt;/sup&gt;), a biomass burning tracer was found higher at Kol than at Kgp. Sum of secondary aerosols sulphate (SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt;), nitrate (NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt;) and ammonium (NH&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;+&lt;/sup&gt;) was higher at Kol than Kgp with relative concentration of SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2-&lt;/sup&gt; being higher than NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;-&lt;/sup&gt; at Kgp which was vice-versa at Kol. Examination of carbonaceous aerosols showed three times higher concentration of organic carbon (OC) than elemental carbon (EC) with monthly mean of OC/EC ratio &gt; 2, indicating likely formation of secondary organic carbon formation. Seasonal influence of biomass burning inferred from nss&amp;#8211;K&lt;sup&gt;+&lt;/sup&gt; (OC/EC) ratio relationship indicated dissimilarity in seasonality of biomass burning at Kgp (Kol). PMF resolved sources for Kgp constituted of secondary aerosol emissions, biomass burning, fugitive dust, marine aerosols, crustal dust and emissions from brick kilns while for Kol factors constituted of burning of waste, resuspended paved road dust, coal combustion, sea spray aerosols, vehicular emissions and biomass burning.&lt;/p&gt;

scholarly journals One-year observations of carbonaceous and nitrogenous components and major ions in the aerosols from subtropical Okinawa Island, an outflow region of Asian dusts

2014 ◽  
Vol 14 (4) ◽  
pp. 1819-1836 ◽  
Author(s):  
B. Kunwar ◽  
K. Kawamura
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Significant Contribution ◽  
Major Ions ◽  
Atmospheric Transport ◽  
Water Soluble ◽  
Anthropogenic Sources ◽  
Marine Biota ◽  
Okinawa Island ◽  
Outflow Region

Abstract. Ambient aerosol samples (TSP, n = 50) were collected for 12 months at subtropical Okinawa Island, Japan, an outflow region of Asian dusts in the western North Pacific and analysed for organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), water-soluble total nitrogen (WSTN), water-soluble organic nitrogen (WSON) and major ions to better understand the formation and transformation of East Asian aerosols during long-range atmospheric transport. Concentration ranges of these components are; OC: 0.76–7.1 μg m−3 (av. 1.7 ± 1.0 μg m−3), EC: 0.07–0.96 μg m−3 (0.28 ± 0.19 μg m−3), WSOC: 0.27–1.9 μg m−3 (0.73 ± 0.38 μg m−3), WSTN: 0.77 to 3.0 μg m−3 (0.58 ± 0.46 μg m−3) and WSON: 0.0–2.2 μg m−3 (0.12 ± 0.23 μg m−3). Higher OC concentrations were obtained in active biota seasons; spring (av. 2.4 μg m−3) and summer (1.8 μg m−3). EC and WSOC concentrations maximized in spring (av. 0.41 μg m−3 and 0.95 μg m−3, respectively) followed by winter (0. 70 and 0.90 μg m−3) whereas they became lowest in summer (0.19 and 0.52 μg m−3). In contrast, WSTN concentrations were highest in winter (0.86 μg m−3) and lowest in summer (0.37 μg m−3) and autumn (0.34 μg m−3). Concentrations of WSON are higher in early summer (av. 0.26 μg m−3) due to the emission from marine biota. The high ratios of OC / EC (av. 7.6) and WSOC / OC (44%) suggest a secondary formation of organic aerosols. Strong correlation between OC and MSA- (0.81) in spring suggests that springtime aerosols are influenced by additional marine and terrestrial biogenic sources. The positive correlation of Ca2+ and TSP in spring (r = = 0.81) demonstrates a significant contribution of Asian dust whereas high abundances of NO3- and nss-SO42- in winter suggest an important contribution from anthropogenic sources including biomass burning, vehicular emission and coal combustion. NH4-N/WSTN ratios peaked in winter (0.56), indicating a significant contribution of biomass burning to WSTN in cold season. In contrast, higher NO3-N/WSTN ratio in spring than winter suggests that the atmospheric transport of vehicular emissions maximizes in spring. Correlation analyses of major ions suggest that NH4+ and Ca2+ play major role in the neutralization of acidic aerosols forming NH4HSO4, (NH4)2SO4 and CaSO4.

scholarly journals Measurement Report: Optical properties and sources of water-soluble brown carbon in Tianjin, North China: insights from organic molecular compositions

2022 ◽  
Author(s):  
Junjun Deng ◽  
Hao Ma ◽  
Xinfeng Wang ◽  
Shujun Zhong ◽  
Zhimin Zhang ◽  
...  
Keyword(s):  
Optical Properties ◽  
Biomass Burning ◽  
Light Absorption ◽  
Radiative Forcing ◽  
North China ◽  
Water Soluble ◽  
Formation Mechanisms ◽  
Chemical Compositions ◽  
Brown Carbon ◽  
Near Ultraviolet

Abstract. Brown carbon (BrC) aerosols exert vital impacts on climate change and atmospheric photochemistry due to their light absorption in the wavelength range from near-ultraviolet (UV) to visible light. However, the optical properties and formation mechanisms of ambient BrC remain poorly understood, limiting the estimation of their radiative forcing. In the present study, fine aerosols (PM2.5) were collected during 2016–2017 on a day/night basis over urban Tianjin, a megacity in North China, to obtain seasonal and diurnal patterns of atmospheric water-soluble BrC. There were obvious seasonal but no evident diurnal variations in light absorption properties of BrC. In winter, BrC showed much stronger light absorbing ability since mass absorption efficiency at 365 nm (MAE365) (1.54 ± 0.33 m2 g−1), which was 1.8 times larger than that (0.84 ± 0.22 m2 g−1) in summer. Direct radiative effects by BrC absorption relative to black carbon in the UV range were 54.3 ± 16.9 % and 44.6 ± 13.9 %, respectively. In addition, five fluorescent components in BrC, including three humic-like fluorophores and two protein-like fluorophores were identified with excitation-emission matrix fluorescence spectrometry and parallel factor (PARAFAC) analysis. The lowly-oxygenated components contributed more to winter and nighttime samples, while more-oxygenated components increased in summer and daytime samples. The higher humification index (HIX) together with lower biological index (BIX) and fluorescence index (FI) suggest that the chemical compositions of BrC were associated with a high aromaticity degree in summer and daytime due to photobleaching. Fluorescent properties indicate that wintertime BrC were predominantly affected by primary emissions and fresh secondary organic aerosol (SOA), while summer ones were more influenced by aging processes. Results of source apportionments using organic molecular compositions of the same set of aerosols reveal that fossil fuel combustion and aging processes, primary bioaerosol emission, biomass burning, and biogenic and anthropogenic SOA formation were the main sources of BrC. Biomass burning contributed much larger to BrC in winter and at nighttime, while biogenic SOA contributed more in summer and at daytime. Especially, our study highlights that primary bioaerosol emission is an important source of BrC in urban Tianjin in summer.

scholarly journals One-year observations of carbonaceous and nitrogenous components and major ions in the aerosols from subtropical Okinawa Island, an outflow region of Asian dusts

2013 ◽  
Vol 13 (8) ◽  
pp. 22059-22106
Author(s):  
B. Kunwar ◽  
K. Kawamura
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Major Ions ◽  
Average Concentration ◽  
Water Soluble ◽  
Anthropogenic Sources ◽  
Marine Biota ◽  
Okinawa Island ◽  
Correlation Analyses ◽  
Outflow Region

Abstract. Ambient aerosol samples (TSP, n=50), collected at subtropical Okinawa Island, Japan, an outflow region of Asian dusts in the western North Pacific, were studied for organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), water-soluble total nitrogen (WSTN), water-soluble organic nitrogen (WSON) and major ions to better understand the long-range atmospheric transport and formation and transformation pathways of East Asian aerosols. Concentrations of OC, EC, WSOC, WSTN and WSON ranged from 0.76 to 7.1 μg m−3 (av. 1.74 ± 1.03 μg m−3), 0.07–0.96 μg m−3 (0.28 ± 0.19 μg m−3), 0.27–1.9 μg m−3 (0.73 ± 0.38 μg m−3), 0.77 to 3.03 μg m−3 (0.58 ± 0.46 μg m−3) and 0 to 2.2 μg m−3 (0.12 ± 0.23 μg m−3), respectively. The average concentration of OC is higher in growing seasons; spring (2.36 μg m−3) and summer (1.79 μg m−3). Similarly, the highest concentrations of EC and WSOC were found in spring (av. 0.41 μg m−3 and 0.95 μg m−3, respectively) followed by winter (0.37 and 0.90 μg m−3) whereas the lowest concentrations were found in summer (0.19 and 0.52 μg m−3, respectively). In contrast, higher concentrations of WSTN were observed in winter (0.86 μg m−3) and lower concentrations were observed in summer (0.37 μg m−3) and autumn (0.34 μg m−3). Similarly, higher concentrations of WSON were observed in early summer (av. 0.26 μg m−3) due to the emission from marine biota. The high OC/EC (av. 7.6) and WSOC/OC (44%) ratios suggest the secondary formation of organic aerosols. The OC/EC ratios, correlation analyses between OC and EC (r = 0.81), and OC and MSA- (0.81) in spring suggest that springtime aerosols are influenced by additional marine and terrestrial biogenic sources. The correlation analyses of Ca2+ and TSP in spring suggests a significant influence from dust whereas the higher concentrations of NO3− and nss-SO42− in winter suggest the influence from anthropogenic sources including biomass burning, vehicular emission and coal combustion. NH4-N/WSTN ratios peaked in winter (0.56), indicating an important contribution of biomass burning to WSTN in cold season. In contrast, higher NO3-N/WSTN ratio in spring than winter suggests that vehicular emissions are significant in spring. Correlation analyses of major ions suggest that \\NH4+ and Ca2+ play major role in the neutralization of aerosols forming NH4HSO4, (NH4)2SO4 and CaSO4.

scholarly journals Organic and inorganic markers and stable C-, N-isotopic compositions of tropical coastal aerosols from megacity Mumbai: sources of organic aerosols and atmospheric processing

2012 ◽  
Vol 12 (8) ◽  
pp. 20593-20630 ◽  
Author(s):  
S. G. Aggarwal ◽  
K. Kawamura ◽  
G. S. Umarji ◽  
E. Tachibana ◽  
R. S. Patil ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Biomass Burning ◽  
Winter Season ◽  
Organic Aerosols ◽  
Inorganic Ions ◽  
Water Soluble ◽  
Total Carbon ◽  
Chemical Compositions ◽  
Diurnal Changes ◽  
Positive Correlation

Abstract. To better understand the sources of PM10 samples from Mumbai, India, aerosol chemical compositions, i.e. total carbon (TC), organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and inorganic ions were studied together with specific markers such as methanesulfonate (MSA), oxalic acid (C2), azelaic acid (C9), and levoglucosan. The results revealed that biofuel/biomass burning and fossil fuel combustion are the major sources of the Mumbai aerosols. Nitrogen-isotopic (δ15N) composition of aerosol total nitrogen, which ranged from 18.1 to 25.4‰, also suggest that biofuel/biomass burning is the dominant source in both summer and winter seasons. Aerosol mass concentrations of major species increased 3–4 times in winter compared to summer, indicating an enhanced emission from these sources in winter season. Photochemical production tracers, C2 diacid and nssSO42− do not show diurnal changes. Concentrations of C2 diacid and WSOC show a strong correlation (r2 = 0.95). In addition, WSOC to OC (or TC) ratios remain almost constant for day- (0.37 ± 0.06 (0.28 ± 0.04)) and nighttime (0.38 ± 0.07 (0.28 ± 0.06)), suggesting that mixing of fresh secondary organic aerosols is not significant rather the Mumbai aerosols are photochemically well processed. Concentrations of MSA and C9 diacid present a positive correlation (r2 = 0.75), indicating a marine influence on Mumbai aerosols in addition to local/regional influence. Backward air mass trajectory analyses further suggested that the Mumbai aerosols are largely influenced by long-range continental and regional transport. Stable C-isotopic ratios (δ13C) of TC ranged from −27.0 to −25.4‰ with slightly lower average (−26.5 ± 0.3‰) in summer than in winter (−25.9 ± 0.3‰). Positive correlation between WSOC/TC ratios and δ13C values suggested that the increment in δ13C of wintertime TC may be caused by prolonged photochemical processing of organic aerosols in this season. This study suggests that in winter, the tropical aerosols are more aged due to longer residence time in the atmosphere than in the summer aerosols.

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