scholarly journals Cloud condensation nucleus activation properties of biogenic secondary organic aerosol

2005 ◽  
Vol 110 (D7) ◽  
Author(s):  
Timothy M. VanReken
Keyword(s):  
Secondary Organic Aerosol ◽  
Condensation Nucleus ◽  
Organic Aerosol ◽  
Cloud Condensation Nucleus

scholarly journals Cloud condensation nucleus activity of secondary organic aerosol particles mixed with sulfate

2007 ◽  
Vol 34 (24) ◽  
Author(s):  
Stephanie M. King ◽  
Thomas Rosenoern ◽  
John E. Shilling ◽  
Qi Chen ◽  
Scot T. Martin
Keyword(s):  
Secondary Organic Aerosol ◽  
Aerosol Particles ◽  
Condensation Nucleus ◽  
Organic Aerosol ◽  
Cloud Condensation Nucleus

scholarly journals Widening the gap between measurement and modelling of secondary organic aerosol properties?

2010 ◽  
Vol 10 (6) ◽  
pp. 2577-2593 ◽  
Author(s):  
N. Good ◽  
D. O. Topping ◽  
J. Duplissy ◽  
M. Gysel ◽  
N. K. Meyer ◽  
...  
Keyword(s):  
Surface Tension ◽  
Water Activity ◽  
Condensation Nucleus ◽  
Organic Aerosol ◽  
Solute Concentration ◽  
Complex Model ◽  
Cloud Condensation Nucleus ◽  
Saturated Water ◽  
Cloud Activation ◽  
Ccn Activity

Abstract. The link between measured sub-saturated hygroscopicity and cloud activation potential of secondary organic aerosol particles produced by the chamber photo-oxidation of α-pinene in the presence or absence of ammonium sulphate seed aerosol was investigated using two models of varying complexity. A simple single hygroscopicity parameter model and a more complex model (incorporating surface effects) were used to assess the detail required to predict the cloud condensation nucleus (CCN) activity from the sub-saturated water uptake. Sub-saturated water uptake measured by three hygroscopicity tandem differential mobility analyser (HTDMA) instruments was used to determine the water activity for use in the models. The predicted CCN activity was compared to the measured CCN activation potential using a continuous flow CCN counter. Reconciliation using the more complex model formulation with measured cloud activation could be achieved widely different assumed surface tension behavior of the growing droplet; this was entirely determined by the instrument used as the source of water activity data. This unreliable derivation of the water activity as a function of solute concentration from sub-saturated hygroscopicity data indicates a limitation in the use of such data in predicting cloud condensation nucleus behavior of particles with a significant organic fraction. Similarly, the ability of the simpler single parameter model to predict cloud activation behaviour was dependent on the instrument used to measure sub-saturated hygroscopicity and the relative humidity used to provide the model input. However, agreement was observed for inorganic salt solution particles, which were measured by all instruments in agreement with theory. The difference in HTDMA data from validated and extensively used instruments means that it cannot be stated with certainty the detail required to predict the CCN activity from sub-saturated hygroscopicity. In order to narrow the gap between measurements of hygroscopic growth and CCN activity the processes involved must be understood and the instrumentation extensively quality assured. It is impossible to say from the results presented here due to the differences in HTDMA data whether: i) Surface tension suppression occurs ii) Bulk to surface partitioning is important iii) The water activity coefficient changes significantly as a function of the solute concentration.

scholarly journals Relating CCN activity, volatility, and droplet growth kinetics of β-caryophyllene secondary organic aerosol

2009 ◽  
Vol 9 (3) ◽  
pp. 795-812 ◽  
Author(s):  
A. Asa-Awuku ◽  
G. J. Engelhart ◽  
B. H. Lee ◽  
S. N. Pandis ◽  
A. Nenes
Keyword(s):  
Growth Kinetics ◽  
Secondary Organic Aerosol ◽  
Active Material ◽  
Organic Aerosol ◽  
Droplet Formation ◽  
Water Soluble ◽  
Cloud Condensation Nucleus ◽  
Droplet Growth ◽  
Kinetics Of ◽  
Ccn Activity

Abstract. This study investigates the droplet formation characteristics of secondary organic aerosol (SOA) formed during the ozonolysis of sesquiterpene β-caryophyllene (with and without hydroxyl radicals present). Emphasis is placed on understanding the role of semi-volatile material on Cloud Condensation Nucleus (CCN) activity and droplet growth kinetics. Aging of β-caryophyllene SOA significantly affects all CCN-relevant properties measured throughout the experiments. Using a thermodenuder and two CCN instruments, we find that CCN activity is a strong function of temperature (activation diameter at ~0.6% supersaturation: 100±10 nm at 20°C and 130±10 nm at 35°C), suggesting that the hygroscopic fraction of the SOA is volatile. The water-soluble organic carbon (WSOC) is extracted from the SOA and characterized with Köhler Theory Analysis (KTA); the results suggest that the WSOC is composed of low molecular weight (<200 g mol−1) slightly surface-active material that constitute 5–15% of the SOA mass. These properties are similar to the water-soluble fraction of monoterpene SOA, suggesting that predictive understanding of SOA CCN activity requires knowledge of the WSOC fraction but not its exact speciation. Droplet growth kinetics of the CCN are found to be strongly anticorrelated with WSOC fraction, suggesting that the insoluble material in the SOA forms a kinetic barrier that delays droplet growth. Overall, volatilization effects can increase activation diameters by 30%, and depress droplet growth rate by a factor of two; these results may have important implications for the droplet formation characteristics of SOA, and the atmospheric relevance of CCN measurements carried out at temperatures different from ambient.

scholarly journals Widening the gap between measurement and modelling of secondary organic aerosol properties?

2009 ◽  
Vol 9 (5) ◽  
pp. 22619-22657
Author(s):  
N. Good ◽  
D. O. Topping ◽  
J. Duplissy ◽  
M. Gysel ◽  
N. K. Meyer ◽  
...  
Keyword(s):  
Surface Tension ◽  
Water Activity ◽  
Condensation Nucleus ◽  
Organic Aerosol ◽  
Solute Concentration ◽  
Complex Model ◽  
Cloud Condensation Nucleus ◽  
Saturated Water ◽  
Cloud Activation ◽  
Ccn Activity

Abstract. The link between measured sub-saturated hygroscopicity and cloud activation potential of secondary organic aerosol particles produced by the chamber photo-oxidation of α-pinene in the presence or absence of ammonium sulphate seed aerosol was investigated using two models of varying complexity. A simple single hygroscopicity parameter model and a more complex model (incorporating surface effects) were used to assess the detail required to predict the cloud condensation nucleus (CCN) activity from the sub-saturated water uptake. Sub-saturated water uptake measured by three hygroscopicity tandem differential mobility analyser (HTDMA) instruments was used to determine the water activity for use in the models. The predicted CCN activity was compared to the measured CCN activation potential using a continuous flow CCN counter. Reconciliation using the more complex model formulation with measured cloud activation required widely different assumed surface tension behavior of the growing droplet; this was entirely determined by the instrument used as the source of water activity data. This unreliable derivation of the water activity as a function of solute concentration from sub-saturated hygroscopicity data indicates a limitation in the use of such data in predicting cloud condensation nucleus behavior of particles with a significant organic fraction. Similarly, the ability of the simpler single parameter model to predict cloud activation behaviour was dependent on the instrument used to measure sub-saturated hygroscopicity and the relative humidity used to provide the model input. However, agreement was observed for inorganic salt solution particles, which were measured by all instruments in agreement with theory. The difference in HTDMA data from proven instruments means that it cannot be stated with certainty the detail required to predict the CCN activity from sub-saturated hygroscopicity. In order to narrow the gap between measurements of hygroscopic growth and CCN activity the processes involved must be understood. It is impossible to say from the results presented here whether: i) Surface tension suppression occurs ii) Bulk to surface partitioning is important iii) The water activity coefficient changes significantly as a function of the solute concentration.

scholarly journals Towards closing the gap between hygroscopic growth and activation for secondary organic aerosol: Part 1 – Evidence from measurements

2009 ◽  
Vol 9 (12) ◽  
pp. 3987-3997 ◽  
Author(s):  
H. Wex ◽  
M. D. Petters ◽  
C. M. Carrico ◽  
E. Hallbauer ◽  
A. Massling ◽  
...  
Keyword(s):  
Pure Water ◽  
Condensation Nucleus ◽  
Organic Aerosol ◽  
Cloud Condensation Nucleus ◽  
Hygroscopic Growth ◽  
The Past ◽  
Particle Activation ◽  
Closing The Gap ◽  
Scattering Signal ◽  
Made In

Abstract. Secondary Organic Aerosols (SOA) studied in previous laboratory experiments generally showed only slight hygroscopic growth, but a much better activity as a CCN (Cloud Condensation Nucleus) than indicated by the hygroscopic growth. This discrepancy was examined at LACIS (Leipzig Aerosol Cloud Interaction Simulator), using a portable generator that produced SOA particles from the ozonolysis of α-pinene, and adding butanol or butanol and water vapor during some of the experiments. The light scattering signal of dry SOA-particles was measured by the LACIS optical particle spectrometer and was used to derive a refractive index for SOA of 1.45. LACIS also measured the hygroscopic growth of SOA particles up to 99.6% relative humidity (RH), and a CCN counter was used to measure the particle activation. SOA-particles were CCN active with critical diameters of e.g. 100 nm and 55 nm at super-saturations of 0.4% and 1.1%, respectively. But only slight hygroscopic growth with hygroscopic growth factors ≤1.05 was observed at RH<98% RH. At RH>98%, the hygroscopic growth increased stronger than would be expected if a constant hygroscopicity parameter for the particle/droplet solution was assumed. An increase of the hygroscopicity parameter by a factor of 4–6 was observed in the RH-range from below 90% to 99.6%, and this increase continued for increasingly diluted particle solutions for activating particles. This explains an observation already made in the past: that the relation between critical super-saturation and dry diameter for activation is steeper than what would be expected for a constant value of the hygroscopicity. Combining measurements of hygroscopic growth and activation, it was found that the surface tension that has to be assumed to interpret the measurements consistently is greater than 55 mN/m, possibly close to that of pure water, depending on the different SOA-types produced, and therefore only in part accounts for the discrepancy between hygroscopic growth and CCN activity observed for SOA particles in the past.

Influence of Functional Groups on Organic Aerosol Cloud Condensation Nucleus Activity

2014 ◽  
Vol 48 (17) ◽  
pp. 10182-10190 ◽  
Author(s):  
Sarah R. Suda ◽  
Markus D. Petters ◽  
Geoffrey K. Yeh ◽  
Christen Strollo ◽  
Aiko Matsunaga ◽  
...  
Keyword(s):  
Functional Groups ◽  
Condensation Nucleus ◽  
Organic Aerosol ◽  
Cloud Condensation Nucleus ◽  
Aerosol Cloud

scholarly journals Relating CCN activity, volatility, and droplet growth kinetics of β-caryophyllene secondary organic aerosol

2008 ◽  
Vol 8 (3) ◽  
pp. 10105-10151 ◽  
Author(s):  
A. Asa-Awuku ◽  
G. J. Engelhart ◽  
B. H. Lee ◽  
S. N. Pandis ◽  
A. Nenes
Keyword(s):  
Growth Kinetics ◽  
Secondary Organic Aerosol ◽  
Active Material ◽  
Organic Aerosol ◽  
Droplet Formation ◽  
Water Soluble ◽  
Cloud Condensation Nucleus ◽  
Droplet Growth ◽  
Kinetics Of ◽  
Ccn Activity

Abstract. This study investigates the droplet formation characteristics of secondary organic aerosol (SOA) formed during the ozonolysis of sesquiterpene β-caryophyllene (with and without hydroxyl radicals present). Emphasis is placed on understanding the role of semi-volatile material on Cloud Condensation Nucleus (CCN) activity and droplet growth kinetics. Aging of β-caryophyllene SOA significantly affects all CCN-relevant properties measured throughout the experiments. Using a thermodenuder and two CCN instruments, we find that CCN activity is a strong function of temperature (activation diameter at ~0.6% supersaturation: 100±10 nm at 20°C and 130±10 nm at 35°C), suggesting that the hygroscopic fraction of the SOA is volatile. The water-soluble organic carbon (WSOC) is extracted from the SOA and characterized with Köhler Theory Analysis (KTA); the results suggest that the WSOC is composed of low molecular weight (<200 g mol−1) slightly surface-active material that constitute 5–15% of the SOA mass. These properties are similar to the water-soluble fraction of monoterpene SOA, suggesting that predictive understanding of SOA CCN activity requires knowledge of the WSOC fraction but not its exact speciation. Droplet growth kinetics of the CCN are found to be strongly anticorrelated with WSOC fraction, suggesting that the insoluble material in the SOA forms a kinetic barrier that delays droplet growth. These results have important implications for the droplet formation characteristics of SOA, and the atmospheric relevance of CCN measurements carried out at temperatures different from ambient.

scholarly journals Secondary organic aerosol formation from biomass burning emissions

2019 ◽  
Author(s):  
Christopher Y. Lim ◽  
David H. Hagan ◽  
Matthew M. Coggon ◽  
Abigail R. Koss ◽  
Kanako Sekimoto ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Secondary Organic Aerosol ◽  
Total Concentration ◽  
Organic Aerosol ◽  
Oh Radicals ◽  
Aerosol Formation ◽  
Atmospheric Aging ◽  
Aerosol Mass ◽  
Photochemical Aging ◽  
Organic Gases

Abstract. Biomass burning is an important source of aerosol and trace gases to the atmosphere, but how these emissions change chemically during their lifetimes is not fully understood. As part of the Fire Influence on Regional and Global Environments Experiment (FIREX 2016), we investigated the effect of photochemical aging on biomass burning organic aerosol (BBOA), with a focus on fuels from the western United States. Emissions were sampled into a small (150 L) environmental chamber and photochemically aged via the addition of ozone and irradiation by 254 nm light. While some fraction of species undergoes photolysis, the vast majority of aging occurs via reaction with OH radicals, with total OH exposures corresponding to the equivalent of up to 10 days of atmospheric oxidation. For all fuels burned, large and rapid changes are seen in the ensemble chemical composition of BBOA, as measured by an aerosol mass spectrometer (AMS). Secondary organic aerosol (SOA) formation is seen for all aging experiments and continues to grow with increasing OH exposure, but the magnitude of the SOA formation is highly variable between experiments. This variability can be explained well by a combination of experiment-to-experiment differences in OH exposure and the total concentration of non-methane organic gases (NMOGs) in the chamber before oxidation, measured by PTR-ToF-MS (r2 values from 0.64 to 0.83). From this relationship, we calculate the fraction of carbon from biomass burning NMOGs that is converted to SOA as a function of equivalent atmospheric aging time, with carbon yields ranging from 24 ± 4 % after 6 hours to 56 ± 9 % after 4 days.

scholarly journals Aging of atmospheric aerosols and the role of iron in catalyzing brown carbon formation

2021 ◽  
Author(s):  
Hind A. A. Al-Abadleh
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Atmospheric Aerosols ◽  
Secondary Organic Aerosol ◽  
Organic Aerosol ◽  
Atmospheric Oxidation ◽  
Carbon Formation ◽  
Brown Carbon ◽  
Volatile Organic

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...

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