scholarly journals Radical-Initiated Brown Carbon Formation in Sunlit Carbonyl–Amine–Ammonium Sulfate Mixtures and Aqueous Aerosol Particles

Author(s):  
Natalie G. Jimenez ◽  
Kyle D. Sharp ◽  
Tobin Gramyk ◽  
Duncan Z. Ugland ◽  
Matthew-Khoa Tran ◽  
...  
2020 ◽  
Author(s):  
David O. De Haan ◽  
Lelia N. Hawkins ◽  
Kevin Jansen ◽  
Hannah G. Welsh ◽  
Raunak Pednekar ◽  
...  

Abstract. Alpha-dicarbonyl compounds are believed to form brown carbon in the atmosphere via reactions with ammonium sulfate (AS) in cloud droplets and aqueous aerosol particles. In this work, brown carbon formation in AS and other aerosol particles was quantified as a function of relative humidity (RH) during exposure to gas-phase glyoxal (GX) in chamber experiments. Under dry conditions (RH 


2020 ◽  
Vol 20 (16) ◽  
pp. 9581-9590
Author(s):  
David O. De Haan ◽  
Lelia N. Hawkins ◽  
Kevin Jansen ◽  
Hannah G. Welsh ◽  
Raunak Pednekar ◽  
...  

Abstract. Alpha-dicarbonyl compounds are believed to form brown carbon in the atmosphere via reactions with ammonium sulfate (AS) in cloud droplets and aqueous aerosol particles. In this work, brown carbon formation in AS and other aerosol particles was quantified as a function of relative humidity (RH) during exposure to gas-phase glyoxal (GX) in chamber experiments. Under dry conditions (RH < 5 %), solid AS, AS–glycine, and methylammonium sulfate (MeAS) aerosol particles brown within minutes upon exposure to GX, while sodium sulfate particles do not. When GX concentrations decline, browning goes away, demonstrating that this dry browning process is reversible. Declines in aerosol albedo are found to be a function of [GX]2 and are consistent between AS and AS–glycine aerosol. Dry methylammonium sulfate aerosol browns 4 times more than dry AS aerosol, but deliquesced AS aerosol browns much less than dry AS aerosol. Optical measurements at 405, 450, and 530 nm provide an estimated Ångstrom absorbance coefficient of -16±4. This coefficient and the empirical relationship between GX and albedo are used to estimate an upper limit to global radiative forcing by brown carbon formed by 70 ppt GX reacting with AS (+7.6×10-5 W m−2). This quantity is < 1 % of the total radiative forcing by secondary brown carbon but occurs almost entirely in the ultraviolet range.


Author(s):  
Yan Gao ◽  
Zhixing Wang ◽  
Yingbo Li ◽  
Haiyan Luo ◽  
Zhimao Zhou

2013 ◽  
Vol 48 (2) ◽  
pp. 985-993 ◽  
Author(s):  
Michelle H. Powelson ◽  
Brenna M. Espelien ◽  
Lelia N. Hawkins ◽  
Melissa M. Galloway ◽  
David O. De Haan

2020 ◽  
Vol 4 (7) ◽  
pp. 1104-1113
Author(s):  
Daisy N. Grace ◽  
Emily N. Lugos ◽  
Shiqing Ma ◽  
Daniel R. Griffith ◽  
Heidi P. Hendrickson ◽  
...  

Author(s):  
Hind A. A. Al-Abadleh

Extensive research has been done on the processes that lead to the formation of secondary organic aerosol (SOA) including atmospheric oxidation of volatile organic compounds (VOCs) from biogenic and anthropogenic...


2016 ◽  
Vol 50 (3) ◽  
pp. 1166-1173 ◽  
Author(s):  
Monique Teich ◽  
Dominik van Pinxteren ◽  
Simonas Kecorius ◽  
Zhibin Wang ◽  
Hartmut Herrmann

2001 ◽  
Vol 1 (1) ◽  
pp. 51-60 ◽  
Author(s):  
J. Joutsensaari ◽  
P. Vaattovaara ◽  
M. Vesterinen ◽  
K. Hämeri ◽  
A. Laaksonen

Abstract. A novel method to characterize the organic composition of aerosol particles has been developed. The method is based on organic vapor interaction with aerosol particles and it has been named an Organic Tandem Differential Mobility Analyzer (OTDMA). The OTDMA method has been tested for inorganic (sodium chloride and ammonium sulfate) and organic (citric acid and adipic acid) particles. Growth curves of the particles have been measured in ethanol vapor and as a comparison in water vapor as a function of saturation ratio. Measurements in water vapor show that sodium chloride and ammonium sulfate as well as citric acid particles grow at water saturation ratios (S) of 0.8 and above, whereas adipic acid particles do not grow at S <  0.96. For sodium chloride and ammonium sulfate particles, a deliquescence point is observed at S = 0.75 and S = 0.79, respectively. Citric acid particles grow monotonously with increasing saturation ratios already at low saturation ratios and no clear deliquescence point is found. For sodium chloride and ammonium sulfate particles, no growth can be seen in ethanol vapor at saturation ratios below 0.93. In contrast, for adipic acid particles, the deliquescence takes place at around S = 0.95 in the ethanol vapor. The recrystallization of adipic acid takes place at S < 0.4. Citric acid particles grow in ethanol vapor similarly as in water vapor; the particles grow monotonously with increasing saturation ratios and no stepwise deliquescence is observed. The results show that the working principles of the OTDMA are operational for single-component aerosols. Furthermore, the results indicate that the OTDMA method may prove useful in determining whether aerosol particles contain organic substances, especially if the OTDMA is operated in parallel with a hygroscopicity TDMA, as the growth of many substances is different in ethanol and water vapors.


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