scholarly journals Cloud droplet activation of secondary organic aerosol

2007 ◽  
Vol 112 (D10) ◽  
Author(s):  
Anthony J. Prenni ◽  
Markus D. Petters ◽  
Sonia M. Kreidenweis ◽  
Paul J. DeMott ◽  
Paul J. Ziemann
Keyword(s):  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Droplet Activation

scholarly journals Large contribution to secondary organic aerosol from isoprene cloud chemistry

2021 ◽  
Vol 7 (13) ◽  
pp. eabe2952
Author(s):  
Houssni Lamkaddam ◽  
Josef Dommen ◽  
Ananth Ranjithkumar ◽  
Hamish Gordon ◽  
Günther Wehrle ◽  
...  
Keyword(s):  
Radiative Forcing ◽  
Flow Reactor ◽  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Global Scale ◽  
Oxidation Products ◽  
Oh Radicals ◽  
Large Contribution ◽  
Cloud Processing

Aerosols still present the largest uncertainty in estimating anthropogenic radiative forcing. Cloud processing is potentially important for secondary organic aerosol (SOA) formation, a major aerosol component: however, laboratory experiments fail to mimic this process under atmospherically relevant conditions. We developed a wetted-wall flow reactor to simulate aqueous-phase processing of isoprene oxidation products (iOP) in cloud droplets. We find that 50 to 70% (in moles) of iOP partition into the aqueous cloud phase, where they rapidly react with OH radicals, producing SOA with a molar yield of 0.45 after cloud droplet evaporation. Integrating our experimental results into a global model, we show that clouds effectively boost the amount of SOA. We conclude that, on a global scale, cloud processing of iOP produces 6.9 Tg of SOA per year or approximately 20% of the total biogenic SOA burden and is the main source of SOA in the mid-troposphere (4 to 6 km).

scholarly journals Cloud droplet activation through oxidation of organic aerosol influenced by temperature and particle phase state

2017 ◽  
Vol 44 (3) ◽  
pp. 1583-1591 ◽  
Author(s):  
Jonathan H. Slade ◽  
Manabu Shiraiwa ◽  
Andrea Arangio ◽  
Hang Su ◽  
Ulrich Pöschl ◽  
...  
Keyword(s):  
Phase State ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Particle Phase ◽  
Droplet Activation

scholarly journals Impact of gas-to-particle partitioning approaches on the simulated radiative effects of biogenic secondary organic aerosol

2015 ◽  
Vol 15 (4) ◽  
pp. 4145-4172 ◽  
Author(s):  
C. E. Scott ◽  
D. V. Spracklen ◽  
J. R. Pierce ◽  
I. Riipinen ◽  
S. D. D'Andrea ◽  
...  
Keyword(s):  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Oxidation Products ◽  
Kinetic Approach ◽  
Particle Phase ◽  
Climatic Effects ◽  
Cloud Droplets ◽  
Volatile Oxidation Products ◽  
Model Treatment

Abstract. The oxidation of biogenic volatile organic compounds (BVOCs) gives a range of products, from semi-volatile to extremely low-volatility compounds. To treat the interaction of these secondary organic vapours with the particle phase, global aerosol microphysics models generally use either a thermodynamic partitioning approach (assuming instant equilibrium between semi-volatile oxidation products and the particle phase) or a kinetic approach (accounting for the size-dependence of condensation). We show that model treatment of the partitioning of biogenic organic vapours into the particle phase, and consequent distribution of material across the size distribution, controls the magnitude of the first aerosol indirect effect (AIE) due to biogenic secondary organic aerosol (SOA). With a kinetic partitioning approach, SOA is distributed according to the existing condensation sink, enhancing the growth of the smallest particles, i.e., those in the nucleation mode. This process tends to increase cloud droplet number concentrations in the presence of biogenic SOA. By contrast, a thermodynamic approach distributes SOA according to pre-existing organic mass, restricting the growth of the smallest particles, limiting the number that are able to form cloud droplets. With an organically medicated new particle formation mechanism, applying a thermodynamic rather than a kinetic approach reduces our calculated global mean AIE due to biogenic SOA by 24%. Our results suggest that the mechanisms driving organic partitioning need to be fully understood in order to accurately describe the climatic effects of SOA.

Cloud droplet activation of polymerized organic aerosol

Tellus B ◽  
2006 ◽  
Vol 58 (3) ◽  
Author(s):  
Markus D. Petters ◽  
Sonia M. Kreidenweis ◽  
Jefferson R. Snider ◽  
Kirsten A. Koehler ◽  
Qiang Wang ◽  
...  
Keyword(s):  
Cloud Droplet ◽  
Organic Aerosol ◽  
Droplet Activation

CCN Spectra, Hygroscopicity, and Droplet Activation Kinetics of Secondary Organic Aerosol Resulting from the 2010 Deepwater Horizon Oil Spill

2012 ◽  
Vol 46 (6) ◽  
pp. 3093-3100 ◽  
Author(s):  
Richard H. Moore ◽  
Tomi Raatikainen ◽  
Justin M. Langridge ◽  
Roya Bahreini ◽  
Charles A. Brock ◽  
...  
Keyword(s):  
Oil Spill ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Deepwater Horizon ◽  
Deepwater Horizon Oil Spill ◽  
Activation Kinetics ◽  
Droplet Activation ◽  
Kinetics Of

scholarly journals Cloud droplet activation of polymerized organic aerosol

Tellus B ◽  
2006 ◽  
Vol 58 (3) ◽  
pp. 196-205 ◽  
Author(s):  
Markus D. Petters ◽  
Sonia M. Kreidenweis ◽  
Jefferson R. Snider ◽  
Kirsten A. Koehler ◽  
Qiang Wang ◽  
...  
Keyword(s):  
Cloud Droplet ◽  
Organic Aerosol ◽  
Droplet Activation

scholarly journals Secondary Organic Aerosol Formation from Acetylene (C<sub>2</sub>H<sub>2</sub>): seed effect on SOA yields due to organic photochemistry in the aerosol aqueous phase

2009 ◽  
Vol 9 (6) ◽  
pp. 1907-1928 ◽  
Author(s):  
R. Volkamer ◽  
P. J. Ziemann ◽  
M. J. Molina
Keyword(s):  
Aqueous Phase ◽  
Liquid Water ◽  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Liquid Water Content ◽  
Water Soluble ◽  
Aerosol Formation ◽  
Cloud Droplets ◽  
Experimental Conditions

Abstract. The lightest Non Methane HydroCarbon (NMHC), i.e., acetylene (C2H2) is found to form secondary organic aerosol (SOA). Contrary to current belief, the number of carbon atoms, n, for a NMHC to act as SOA precursor is lowered to n=2 here. The OH-radical initiated oxidation of C2H2 forms glyoxal (CHOCHO) as the highest yield product, and >99% of the SOA from C2H2 is attributed to CHOCHO. SOA formation from C2H2 and CHOCHO was studied in a photochemical and a dark simulation chamber. Further, the experimental conditions were varied with respect to the chemical composition of the seed aerosols, mild acidification with sulphuric acid (SA, 3<pH<4), and relative humidity (10<RH<90%). The rate of SOA formation is found enhanced by several orders of magnitude in the photochemical system. The SOA yields (YSOA) ranged from 1% to 24% and did not correlate with the organic mass portion of the seed, but increased linearly with liquid water content (LWC) of the seed. For fixed LWC, YSOA varied by more than a factor of five. Water soluble organic carbon (WSOC) photochemistry in the liquid water associated with internally mixed inorganic/WSOC seed aerosols is found responsible for this seed effect. WSOC photochemistry enhances the SOA source from CHOCHO, while seeds containing amino acids (AA) and/or SA showed among the lowest of all YSOA values, and largely suppress the photochemical enhancement on the rate of CHOCHO uptake. Our results give first evidence for the importance of heterogeneous photochemistry of CHOCHO in SOA formation, and identify a potential bias in the currently available YSOA data for other SOA precursor NMHCs. We demonstrate that SOA formation via the aqueous phase is not limited to cloud droplets, but proceeds also in the absence of clouds, i.e., does not stop once a cloud droplet evaporates. Atmospheric models need to be expanded to include SOA formation from WSOC photochemistry of CHOCHO, and possibly other α-dicarbonyls, in aqueous aerosols.

scholarly journals Secondary organic aerosol formation from acetylene (C<sub>2</sub>H<sub>2</sub>): seed effect on SOA yields due to organic photochemistry in the aerosol aqueous phase

2008 ◽  
Vol 8 (4) ◽  
pp. 14841-14892 ◽  
Author(s):  
R. Volkamer ◽  
P. J. Ziemann ◽  
M. J. Molina
Keyword(s):  
Aqueous Phase ◽  
Liquid Water ◽  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Liquid Water Content ◽  
Water Soluble ◽  
Aerosol Formation ◽  
Cloud Droplets ◽  
Experimental Conditions

Abstract. The lightest Non Methane HydroCarbon (NMHC), i.e. acetylene (C2H2) is found to form secondary organic aerosol (SOA). Contrary to current belief, the number of carbon atoms, n, for a NMHC to act as SOA precursor is lowered to n=2 here. The OH-radical initiated oxidation of C2H2 forms glyoxal (CHOCHO) as the highest yield product, and >99% of the SOA from C2H2 is attributed to CHOCHO. SOA formation from C2H2 and CHOCHO was studied in a photochemical and a dark simulation chamber. Further, the experimental conditions were varied with respect to the chemical composition of the seed aerosol, mild acidification with sulphuric acid (SA, 3<pH<4), and relative humidity (10<RH<90%). The rate of SOA formation is found enhanced by several orders of magnitude in the photochemical system. The SOA yields (YSOA) ranged from 1% to 20% and did not correlate with the organic mass portion of the seed, but increased linearly with liquid water content (LWC) of the seed. For fixed LWC, YSOA varied by more than a factor of five. Water soluble organic carbon (WSOC) photochemistry in the liquid water associated with internally mixed inorganic/WSOC seed aerosols is found responsible for this seed effect. WSOC photochemistry enhances the SOA source from CHOCHO, while seeds containing amino acids (AA) and/or SA showed among the lowest of all YSOA values, and largely suppress the photochemical enhancement on the rate of CHOCHO uptake. Our results give first evidence for the importance of heterogeneous photochemistry of CHOCHO in SOA formation, and identify a potential bias in the currently available YSOA data for other SOA precursor NMHCs. We demonstrate that SOA formation via the aqueous phase is not limited to cloud droplets, but proceeds also in the absence of clouds, i.e. does not stop once a cloud droplet evaporates. Atmospheric models need to be expanded to include SOA formation from WSOC photochemistry of CHOCHO, and possibly other α-dicarbonyls, in aqueous aerosols.

scholarly journals In-cloud processes of methacrolein under simulated conditions – Part 3: Hygroscopic and volatility properties of the formed secondary organic aerosol

2009 ◽  
Vol 9 (14) ◽  
pp. 5119-5130 ◽  
Author(s):  
V. Michaud ◽  
I. El Haddad ◽  
K. Sellegri ◽  
P. Laj ◽  
P. Villani ◽  
...  
Keyword(s):  
Reaction Time ◽  
Gas Phase ◽  
Aqueous Phase ◽  
Secondary Organic Aerosol ◽  
Cloud Droplet ◽  
Organic Aerosol ◽  
Hygroscopic Growth ◽  
Reaction Products ◽  
Hygroscopic Properties ◽  
Refractory Compounds

Abstract. The hygroscopic and volatility properties of secondary organic aerosol (SOA) produced from the nebulization of solutions after aqueous phase photooxidation of methacrolein was experimentally studied in a laboratory, using a Volatility-Hygroscopicity Tandem DMA (VHTDMA). The obtained SOA were 80% 100°C-volatile after 5 h of reaction and only 20% 100°C-volatile after 22 h of reaction. The Hygroscopic Growth Factor (HGF) of the SOA produced from the nebulization of solutions after aqueous-phase photooxidation of methacrolein is 1.34–1.43, which is significantly higher than the HGF of SOA formed by gas-phase photooxidation of terpenes, usually found almost hydrophobic. These hygroscopic properties were confirmed for SOA formed by the nebulization of the same solutions where NaCl was added. The hygroscopic properties of the cloud droplet residuals decrease with the reaction time, in parallel with the formation of more refractory compounds. This decrease was mainly attributed to the 250°C-refractive fraction (presumably representative of the highest molecular weight compounds), which evolved from moderately hygroscopic (HGF of 1.52) to less hygroscopic (HGF of 1.36). Oligomerization is suggested as a process responsible for the decrease of both volatility and hygroscopicity with time. The NaCl seeded experiments enabled us to show that 19±4 mg L−1 of SOA was produced after 9.5 h of reaction and 41±9 mg L−1 after 22 h of in-cloud reaction. Because more and more SOA is formed as the reaction time increases, our results show that the reaction products formed during the aqueous-phase OH-oxidation of methacrolein may play a major role in the properties of residual particles upon the droplet's evaporation. Therefore, the specific physical properties of SOA produced during cloud processes should be taken into account for a global estimation of SOA and their atmospheric impacts.

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