0000000000810856
AUTHOR
Wenting Dai
showing 4 related works from this author
Water-Insoluble Organics Dominate Brown Carbon in Wintertime Urban Aerosol of China: Chemical Characteristics and Optical Properties.
2020
The chromophores responsible for light absorption in atmospheric brown carbon (BrC) are not well characterized, which hinders our understanding of BrC chemistry, the links with optical properties, and accurate model representations of BrC to global climate and atmospheric oxidative capacity. In this study, the light absorption properties and chromophore composition of three BrC fractions of different polarities were characterized for urban aerosol collected in Xi'an and Beijing in winter 2013-2014. These three BrC fractions show large differences in light absorption and chromophore composition, but the chromophores responsible for light absorption are similar in Xi'an and Beijing. Water-ins…
Brown Carbon Aerosol in Urban Xi'an, Northwest China: The Composition and Light Absorption Properties.
2018
Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) w…
Determination of n-alkanes, PAHs and hopanes in atmospheric aerosol: evaluation and comparison of thermal desorption GC-MS and solvent extraction GC-…
2019
Organic aerosol (OA) constitutes a large fraction of fine particulate matter (PM) in the urban air. However, the chemical nature and sources of OA are not well constrained. Quantitative analysis of OA is essential for understanding the sources and atmospheric evolution of fine PM, which requires accurate quantification of some organic compounds (e.g., markers). In this study, two analytical approaches, i.e., thermal desorption (TD) gas chromatography-mass spectrometry (GC-MS) and solvent extract (SE) GC-MS were evaluated for the determination of n-alkanes, polycyclic aromatic hydrocarbons (PAHs), and hopanes in ambient aerosol. For the SE approach, the recovery obtained is 89.3–101.5&…
Contrasting sources and processes of particulate species in haze days with low and high relative humidity in winter time Beijing
2020
Abstract. Although there are many studies of particulate matter (PM) pollution in Beijing, the sources and processes of secondary PM species during haze periods remain unclear. Limited studies have investigated the PM formation in highly-polluted environments under low and high relative humidity (RH) conditions. Herein, we present a systematic comparison of species in submicron particles (PM1) in wintertime Beijing (29 December 2014 to 28 February 2015) for clean periods and pollution periods under low and high RH conditions. PM1 species were measured with an aerosol chemical species monitor (ACSM) and an aethalometer. Sources and processes for organic aerosol (OA) were resolved by positive…