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Havers, N.; Burba, P.; Lambert, Jörg; Klockow, D.

doi:10.1023/a:1005875225800

Cited by 299 publications

(94 citation statements)

References 16 publications

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“…Decesari et al (2001) identified up to 40 % of WSOC as polycarboxylic acids resembling the molecular structures of humic materials using the same HNMR technique. The similarity of the polycarboxylic acid fraction to humic materials, observed in several studies (Mukai and Ambe, 1986;Havers et al, 1998;Facchini et al, 1999;Gelencsér et al, 2000;Krivácsy et al, 2000;Duarte et al, 2005;Alfarra et al, 2006), has earned this fraction the name HUmic-LIke Substances (HULIS).…”

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confidence: 94%

Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

Zamora

Jacobson

2013

Atmos. Chem. Phys.

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The hygroscopic growth of atmospheric particles affects atmospheric chemistry and Earth's climate. Water-soluble organic carbon (WSOC) constitutes a significant fraction of the dry submicron mass of atmospheric aerosols, thus affecting their water uptake properties. Although the WSOC fraction is comprised of many compounds, a set of model substances can be used to describe its behavior. For this study, mixtures of Nordic aquatic fulvic acid reference (NAFA) and Fluka humic acid (HA), with various combinations of inorganic salts (sodium chloride and ammonium sulfate) and other representative organic compounds (levoglucosan and succinic acid), were studied. We measured the equilibrium water vapor pressure over bulk solutions of these mixtures as a function of temperature and solute concentration. New water activity (a_w) parameterizations and hygroscopic growth curves at 25 °C were calculated from these data for particles of equivalent composition. We examined the effect of temperature on the water activity and found a maximum variation of 9% in the 0–30 °C range, and 2% in the 20–30 °C range. Five two-component mixtures were studied to understand the effect of adding a humic substance (HS), such as NAFA and HA, to an inorganic salt or a saccharide. The deliquescence point at 25 °C for HS-inorganic mixtures did not change significantly from that of the pure inorganic species. However, the hygroscopic growth of HA / inorganic mixtures was lower than that exhibited by the pure salt, in proportion to the added mass of HA. The addition of NAFA to a highly soluble solute (ammonium sulfate, sodium chloride or levoglucosan) in water had the same effect as the addition of HA to the inorganic species for most of the water activity range studied. Yet, the water uptake of these NAFA mixtures transitioned to match the growth of the pure salt or saccharide at high a_w values. The remaining four mixtures were based on chemical composition data for different aerosol types. As expected, the two solutions representing organic aerosols (40% HS/40% succinic acid/20% levoglucosan) showed lower water uptake than the two solutions representing biomass burning aerosols (25% HS/27% succinic acid/18% levoglucosan/30% ammonium sulfate). However, interactions in multicomponent solutions may be responsible for the large variation of the relative water uptake of identical mixtures containing different HSs above a water activity of 0.95. The ZSR (Zdanovskii, Stokes, and Robinson) model was able to predict reasonably well the hygroscopic growth of all the mixtures below a_w = 0.95, but produced large deviations for some multicomponent mixtures at higher values

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confidence: 94%

Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

Zamora

Jacobson

2013

Atmos. Chem. Phys.

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“…The advantage of SPE is the re-moval of inorganic ions and the collection of the organic fraction, facilitating subsequent characterization of the chemical and physical properties of HULIS. Other methods have also been utilized, such as capillary electrophoresis (Havers et al, 1998a), ultrafiltration (Havers et al, 1998b), ion-exchange chromatography (Decesari et al, 2000), and size-exclusion chromatography (Krivacsy et al, 2000;Samburova et al, 2005a, b).…”

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confidence: 99%

Sources of humic-like substances in the Pearl River Delta, China: positive matrix factorization analysis of PM2.5 major components and source markers

et al. 2015

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Abstract. Humic-like substances (HULIS), the hydrophobic part of water-soluble organic carbon (WSOC), account for a significant fraction of PM 2.5 mass. Their source studies are so far largely qualitative. In this study, HULIS and WSOC were determined in 100 PM 2.5 samples collected in 2009 at an urban site (Guangzhou) and a suburban site (Nansha) in the Pearl River Delta in South China. The annual average concentration of HULIS was 4.83 and 4.71 µg m −3 , constituting 8.5 and 10.2 % of the PM 2.5 mass, while HULIS-C (the carbon component of HULIS) contributed 48 and 57 % of WSOC at the two sites, respectively. HULIS were found to correlate with biomass burning (BB) tracers (i.e., levoglucosan and K) and secondary species (e.g., SO 2− 4 and NH + 4 ), suggesting its association with BB emissions and secondary formation processes. Sources of HULIS were investigated using positive matrix factorization analysis of PM 2.5 chemical composition data, including major components and source markers. In addition to secondary formation process and BB emissions, residual oil combustion related to shipping was identified for the first time as a significant source of HULIS. Secondary formation process contributed the most, accounting for 49-82 % of ambient HULIS at the two sites in different seasons. BB emissions contributed a seasonal average of 8-28 %, with more contributions observed in the winter months (November-February) due to crop residue burning during harvest season. Residual oil combustion was revealed to be an important source at the suburban site in summer (44 % of HULIS-C) due to its proximity to one of the ports and the shipping lane in the region. Vehicle emissions were found to contribute little to HULIS, but had contributions to the hydrophilic WSOC fraction. The contrast in contributions from different combustion sources to HULIS and hydrophilic WSOC suggests that primary sources of HULIS are linked to inefficient combustion. This source analysis suggests further study of HULIS be focused on secondary formation process and source characteristics of HULIS from BB and residual oil combustion.

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“…There has been growing evidence for the contribution of brown carbon to light absorption in atmospheric aerosols from chemical aerosol measurements and laboratory studies (Mukai and Ambe, 1986;Havers et al, 1998;Hoffer et al, 2006;Alexander et al, 2008;Park et al, 2010).…”

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confidence: 99%

Ionic and carbonaceous compositions of PM10, PM2.5 and PM1.0 at Gosan ABC Superstation and their ratios as source signature

et al. 2012

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Abstract. PM 1.0 , PM 2.5 , and PM 10 were sampled at Gosan ABC Superstation on Jeju Island from August 2007 to September 2008. The carbonaceous aerosols were quantified with the thermal/optical reflectance (TOR) method, which produced five organic carbon (OC) fractions, OC1, OC2, OC3, OC4, and pyrolyzed organic carbon (OP), and three elemental carbon (EC) fractions, EC1, EC2, and EC3. The mean mass concentrations of PM 1.0 , PM 2.5 , and PM 10 were 13.7 µg m −3 , 17.2 µg m −3 , and 28.4 µg m −3 , respectively. The averaged mass fractions of OC and EC were 23.0 % and 10.4 % for PM 1.0 , 22.9 % and 9.8 % for PM 2.5 , and 16.4 % and 6.0 % for PM 10 . Among the OC and EC sub-components, OC2 and EC2+3 were enriched in the fine mode, but OC3 and OC4 in the coarse mode. The filterbased PM 1.0 EC agreed well with black carbon (BC) measured by an Aethalometer, and PM 10 EC was higher than BC, implying less light absorption by larger particles. EC was well correlated with sulfate, resulting in good relationships of sulfate with both aerosol scattering coefficient measured by Nephelometer and BC concentration. Our measurements of EC confirmed the definition of EC1 as char-EC emitted from smoldering combustion and EC2+3 as soot-EC generated from higher-temperature combustion such as motor vehicle exhaust and coal combustion (Han et al., 2010). In particular, EC1 was strongly correlated with potassium, a traditional biomass burning indicator, except during the summer, when the ratio of EC1 to EC2+3 was the lowest. We also found the ratios of major chemical species to be a useful tool to constrain the main sources of aerosols, by which the five air masses were well distinguished: Siberia, Beijing, Shanghai, Yellow Sea, and East Sea types. Except Siberian air, the continental background of the study region, Beijing plumes showed the highest EC1 (and OP) to sulfate ratio, which implies that this air mass had the highest net warming by aerosols of the four air masses. Shanghai-type air, which was heavily influenced by southern China, showed the highest sulfate enhancement. The highest EC2+3/EC1 ratio was found in aged East Sea air, demonstrating a significant influence of motor vehicle emissions from South Korea and Japan and less influence from industrial regions of China. The high ratio results from the longer residence time and less sensitivity to wet scavenging of EC2+3 compared to EC1, indicating that soot-EC could have greater consequence in regionalscale warming.

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Cited by 299 publications

References 16 publications

Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

Sources of humic-like substances in the Pearl River Delta, China: positive matrix factorization analysis of PM<sup>2.5</sup> major components and source markers

Ionic and carbonaceous compositions of PM<sub>10</sub>, PM<sub>2.5</sub> and PM<sub>1.0</sub> at Gosan ABC Superstation and their ratios as source signature

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Untitled

Cited by 299 publications

References 16 publications

Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

Measuring and modeling the hygroscopic growth of two humic substances in mixed aerosol particles of atmospheric relevance

Sources of humic-like substances in the Pearl River Delta, China: positive matrix factorization analysis of PM&lt;sup&gt;2.5&lt;/sup&gt; major components and source markers

Ionic and carbonaceous compositions of PM&lt;sub&gt;10&lt;/sub&gt;, PM&lt;sub&gt;2.5&lt;/sub&gt; and PM&lt;sub&gt;1.0&lt;/sub&gt; at Gosan ABC Superstation and their ratios as source signature

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Sources of humic-like substances in the Pearl River Delta, China: positive matrix factorization analysis of PM<sup>2.5</sup> major components and source markers

Ionic and carbonaceous compositions of PM<sub>10</sub>, PM<sub>2.5</sub> and PM<sub>1.0</sub> at Gosan ABC Superstation and their ratios as source signature