scholarly journals Humidity Dependence of the Condensational Growth of α-Pinene Secondary Organic Aerosol Particles

2021 ◽  
Author(s):  
Yiming Qin ◽  
Jianhuai Ye ◽  
Paul Ohno ◽  
Jinghao Zhai ◽  
Yuemei Han ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Condensational Growth ◽  
Humidity Dependence

Experimental determination of chemical diffusion within secondary organic aerosol particles

2013 ◽  
Vol 15 (8) ◽  
pp. 2983 ◽  
Author(s):  
Evan Abramson ◽  
Dan Imre ◽  
Josef Beránek ◽  
Jacqueline Wilson ◽  
Alla Zelenyuk
Keyword(s):  
Experimental Determination ◽  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Chemical Diffusion ◽  
Organic Aerosol

scholarly journals Volatility and lifetime against OH heterogeneous reaction of ambient Isoprene Epoxydiols-Derived Secondary Organic Aerosol (IEPOX-SOA)

2016 ◽  
Author(s):  
Weiwei Hu ◽  
Brett B. Palm ◽  
Douglas A. Day ◽  
Pedro Campuzano-Jost ◽  
Jordan E. Krechmer ◽  
...  
Keyword(s):  
Flow Reactor ◽  
Secondary Organic Aerosol ◽  
Heterogeneous Reaction ◽  
Ambient Air ◽  
Organic Aerosol ◽  
Amazon Forest ◽  
Reaction Products ◽  
Ambient Conditions ◽  
Forested Areas ◽  
Humidity Dependence

Abstract. Isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) can contribute substantially to organic aerosol (OA) concentrations in forested areas under low NO conditions, hence significantly influencing the regional and global OA budgets, accounting for example for 16–36 % of the submicron OA in the SE US summer. Particle evaporation measurements from a thermodenuder show that the volatility of ambient IEPOX-SOA is lower than that of bulk OA and also much lower than that of known monomer IEPOX-SOA tracer species, indicating that IEPOX-SOA likely exists mostly as oligomers in the aerosol phase. The OH aging process of ambient IEPOX-SOA was investigated with an oxidation flow reactor (OFR). New IEPOX-SOA formation in the reactor was negligible, as the OFR cannot accelerate processes such as aerosol uptake and reactions that do not scale with OH. Simulation results indicate that adding ~ 100 µg m−3 of pure H2SO4 to the ambient air allows to efficiently form IEPOX-SOA in the reactor. The heterogeneous reaction rate coefficient of ambient IEPOX-SOA with OH radical (kOH) was estimated as 4.0 ± 2.0 × 10−13 cm3 molec−1 s−1, which is equivalent to more than a 2-week lifetime. A similar kOH was found for measurements of OH oxidation of ambient Amazon forest air in an OFR. At higher OH exposures in the reactor (> 1 × 1012 molec. cm−3 s), the mass loss of IEPOX-SOA due to heterogeneous reaction was mainly due to revolatilization of fragmented reaction products. We report for the first time OH reactive uptake coefficients (γOH = 0.59 ± 0.33 in SE US and γOH = 0.68 ± 0.38 in Amazon) for SOA under ambient conditions. A relative humidity dependence of kOH and γOH was observed, consistent with surface area-limited OH uptake. No decrease of kOH was observed as OH concentrations increased. These observation of physicochemical properties of IEPOX-SOA can help to constrain OA impact on air quality and climate.

Carbon in southeastern U.S. aerosol particles: Empirical estimates of secondary organic aerosol formation

2008 ◽  
Vol 42 (27) ◽  
pp. 6710-6720 ◽  
Author(s):  
Charles L. Blanchard ◽  
George M. Hidy ◽  
Shelley Tanenbaum ◽  
Eric Edgerton ◽  
Benjamin Hartsell ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Aerosol Formation ◽  
Empirical Estimates ◽  
Secondary Organic Aerosol Formation

scholarly journals The efficiency of secondary organic aerosol particles to act as ice nucleating particles at mixed-phase cloud conditions

2018 ◽  
Author(s):  
Wiebke Frey ◽  
Dawei Hu ◽  
James Dorsey ◽  
M. Rami Alfarra ◽  
Aki Pajunoja ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Organic Aerosol ◽  
Ice Nucleation ◽  
Mixed Phase ◽  
Dust Particles ◽  
Ice Cloud ◽  
Liquid Saturation ◽  
Reference Experiment ◽  
Mixed Phase Clouds

Abstract. Secondary Organic Aerosol (SOA) particles have been found to be efficient ice nucleating particles under the cold conditions of (tropical) upper tropospheric cirrus clouds. Whether they also are efficient at initiating freezing at slightly warmer conditions as found in mixed phase clouds remains undetermined. Here, we study the ice nucleating ability of photo-chemically produced SOA particles with the combination of the Manchester Aerosol and Ice Cloud Chambers. Three SOA systems were tested resembling biogenic/anthropogenic particles and particles of different phase state. After the aerosol particles were formed, they were transferred into the cloud chamber where subsequent quasi-adiabatic cloud evacuations were performed. Additionally, the ice forming abilities of ammonium sulfate and kaolinite were investigated as a reference to test the experimental setup. Clouds were formed in the temperature range of −20 °C to −28.6 °C. Only the reference experiment using dust particles showed evidence of ice nucleation. No ice particles were observed in any other experiment. Thus, we conclude that SOA particles produced under the conditions of the reported experiments are not efficient ice nucleating particles starting at liquid saturation under mixed-phase cloud conditions.

scholarly journals Mechanistic study of secondary organic aerosol components formed from nucleophilic addition reactions of methacrylic acid epoxide

2014 ◽  
Vol 14 (14) ◽  
pp. 19917-19954 ◽  
Author(s):  
A. W. Birdsall ◽  
C. R. Miner ◽  
L. E. Mael ◽  
M. J. Elrod
Keyword(s):  
Methacrylic Acid ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Bulk Solution ◽  
Mechanistic Study ◽  
Similar Reaction ◽  
Specific Chemical ◽  
High Concentrations ◽  
Humidity Dependence ◽  
Acid Esters

Abstract. Recently, methacrylic acid epoxide (MAE) has been proposed as a precursor to an important class of isoprene-derived compounds found in secondary organic aerosol (SOA): 2-methylglyceric acid (2-MG) and a set of oligomers, nitric acid esters and sulfuric acid esters related to 2-MG. However, the specific chemical mechanisms by which MAE could form these compounds have not been previously studied. In order to determine the relevance of these processes to atmospheric aerosol, MAE and 2-MG have been synthesized and a series of bulk solution-phase experiments aimed at studying the reactivity of MAE using nuclear magnetic resonance (NMR) spectroscopy have been performed. The present results indicate that the acid-catalyzed MAE reaction is more than 600 times slower than a similar reaction of an important isoprene-derived epoxide, but is still expected to be kinetically feasible in the atmosphere on more acidic SOA. The specific mechanism by which MAE leads to oligomers was identified, and the reactions of MAE with a number of atmospherically relevant nucleophiles were also investigated. Because the nucleophilic strengths of water, sulfate, alcohols (including 2-MG), and acids (including MAE and 2-MG) in their reactions with MAE were found to be of a similar magnitude, it is expected that a diverse variety of MAE + nucleophile product species may be formed on ambient SOA. Thus, the results indicate that epoxide chain reaction oligomerization will be limited by the presence of high concentrations of non-epoxide nucleophiles (such as water); this finding is consistent with previous environmental chamber investigations of the relative humidity-dependence of 2-MG-derived oligomerization processes and suggests that extensive oligomerization may not be likely on ambient SOA because of other competitive MAE reaction mechanisms.

An amorphous solid state of biogenic secondary organic aerosol particles

Nature ◽  
2010 ◽  
Vol 467 (7317) ◽  
pp. 824-827 ◽  
Author(s):  
Annele Virtanen ◽  
Jorma Joutsensaari ◽  
Thomas Koop ◽  
Jonna Kannosto ◽  
Pasi Yli-Pirilä ◽  
...  
Keyword(s):  
Solid State ◽  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Amorphous Solid ◽  
Organic Aerosol
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