scholarly journals The effect of organic coatings on the cloud condensation nuclei activation of inorganic atmospheric aerosol

1998 ◽  
Vol 103 (D11) ◽  
pp. 13111-13123 ◽  
Author(s):  
Celia N. Cruz ◽  
Spyros N. Pandis
Keyword(s):  
Atmospheric Aerosol ◽  
Cloud Condensation Nuclei ◽  
Organic Coatings ◽  
Condensation Nuclei

scholarly journals Subarctic atmospheric aerosol composition: 3. Measured and modeled properties of cloud condensation nuclei

2010 ◽  
Vol 115 (D4) ◽  
Author(s):  
Lukas Kammermann ◽  
Martin Gysel ◽  
Ernest Weingartner ◽  
Hanna Herich ◽  
Daniel J. Cziczo ◽  
...  
Keyword(s):  
Atmospheric Aerosol ◽  
Cloud Condensation Nuclei ◽  
Condensation Nuclei ◽  
Aerosol Composition

scholarly journals Versatile Aerosol Concentration Enrichment System (VACES) operating as a Cloud Condensation Nuclei (CCN) concentrator. Development and laboratory characterization

2019 ◽  
Author(s):  
Carmen Dameto de España ◽  
Gerhard Steiner ◽  
Harald Schuh ◽  
Constantinos Sioutas ◽  
Regina Hitzenberger
Keyword(s):  
Particle Size ◽  
Atmospheric Aerosol ◽  
Continuous Flow ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Meteorological Conditions ◽  
Condensation Nuclei ◽  
Laboratory Characterization ◽  
Condenser Temperature ◽  
Original Size

Abstract. The ability of atmospheric aerosol particles to act as cloud condensation nuclei (CCN) depends on many factors, including particle size, chemical composition, and meteorological conditions. To expand our knowledge on CCN, it is essential to understand the factors leading to CCN activation. For this purpose a versatile aerosol concentrator enrichment system (VACES) has been modified to select CCN at different supersaturations. The VACES enables to sample CCN particles without altering their chemical and physical properties. The redesigned VACES enriches CCN particles by first passing the aerosol flow to a new saturator and then to a condenser. The activated particles are concentrated by an inertial virtual impactor, and then can be returned to their original size by diffusion-drying. For the calibration, the saturator temperature was fixed at 52 °C and the condenser temperature range was altered from 5 °C to 25 °C to obtain activation curves for NaCl particles of different sizes. Critical water vapour supersaturations can be calculated using the 50 % cutpoint of these curves. Calibration results have also shown that CCN concentrations can be enriched by a factor of approx. 17, which is in agreement with the experimentally determined enrichment factor of the original VACES. The advantage of the re-designed VACES over conventional CCN counters (both static and continuous flow instruments) lies in the substantial enrichment of activated CCN which facilitates further chemical analysis.

scholarly journals Subpollen particles as atmospheric cloud condensation nuclei

2019 ◽  
Vol 55 (4) ◽  
pp. 64-72
Author(s):  
E. F. Mikhailov ◽  
O. A. Ivanova ◽  
E. Yu. Nebosko ◽  
S. S. Vlasenko ◽  
T. I. Ryshkevich
Keyword(s):  
Atmospheric Aerosol ◽  
Size Range ◽  
Cloud Condensation Nuclei ◽  
Pollen Grains ◽  
Submicron Particles ◽  
Liquid Droplets ◽  
Condensation Nuclei ◽  
Condensation Activity ◽  
Cloud Activation ◽  
Plant Pollen

Bioparticles represent a significant fraction of the total atmospheric aerosol. Their size range varies from nanometers (macromolecules) to hundreds of micrometers (plant pollen, vegetation residues) and like other atmospheric aerosol particles, the degree of involvement of bioaerosols in atmospheric processes largely de- pends on their hygroscopic and cloud condensation nuclei properties. In this paper the ability of the pine, birch and rape subpollen particles to act as cloud condensation nuclei are considered. Submicron particles were obtained by aqueous extraction of biological material from pollen grains and subsequent solidification of the atomized liquid droplets. The parameters of cloud activation are determined in the size range of 20-270 nm in the range of water vapor supersaturations 0.1-1.1%. Based on experimental results, the hygroscopicity parameter, characterizing the effect of the chemical composition of the subparticles on their con- densation properties, is determined. The range of the hygroscopic parameter changes was 0.12-0.13. In general, the results of measurements showed that the condensation activity of the subpollen particles is comparable with the condensation activity of secondary organic aerosols and weakly depends on the type of the primary pollen.

scholarly journals Versatile aerosol concentration enrichment system (VACES) operating as a cloud condensation nuclei (CCN) concentrator: development and laboratory characterization

2019 ◽  
Vol 12 (9) ◽  
pp. 4733-4744
Author(s):  
Carmen Dameto de España ◽  
Gerhard Steiner ◽  
Harald Schuh ◽  
Constantinos Sioutas ◽  
Regina Hitzenberger
Keyword(s):  
Particle Size ◽  
Atmospheric Aerosol ◽  
Continuous Flow ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Meteorological Conditions ◽  
Condensation Nuclei ◽  
Laboratory Characterization ◽  
Condenser Temperature ◽  
Original Size

Abstract. The ability of atmospheric aerosol particles to act as cloud condensation nuclei (CCN) depends on many factors, including particle size, chemical composition and meteorological conditions. To expand our knowledge of CCN, it is essential to understand the factors leading to CCN activation. For this purpose, a versatile aerosol concentrator enrichment system (VACES) has been modified to select CCN at different supersaturations. The VACES enables sampling non-volatile CCN particles without altering their chemical and physical properties. The redesigned VACES enriches CCN particles by first passing the aerosol flow to a new saturator and then to a condenser. The activated particles are concentrated by an inertial virtual impactor and then can be returned to their original size by diffusion drying. For the calibration, the saturator temperature was fixed at 52 ∘C and the condenser temperature range was altered from 5 to 25 ∘C to obtain activation curves for NaCl particles of different sizes. Critical water vapour supersaturations can be calculated using the 50 % cut point of these curves. Calibration results have also shown that CCN concentrations can be enriched by a factor of approx. 17, which is in agreement with the experimentally determined enrichment factor of the original VACES. The advantage of the redesigned VACES over conventional CCN counters (both static and continuous flow instruments) lies in the substantial enrichment of activated CCN, which facilitates further chemical analysis.

scholarly journals Cloud condensation nuclei in pristine tropical rainforest air of Amazonia: size-resolved measurements and modeling of atmospheric aerosol composition and CCN activity

2009 ◽  
Vol 9 (1) ◽  
pp. 3811-3870 ◽  
Author(s):  
S. S. Gunthe ◽  
S. M. King ◽  
D. Rose ◽  
Q. Chen ◽  
P. Roldin ◽  
...  
Keyword(s):  
Water Vapor ◽  
Atmospheric Aerosol ◽  
Particle Number ◽  
Tropical Rainforest ◽  
Cloud Condensation Nuclei ◽  
Aerosol Particles ◽  
Condensation Nuclei ◽  
Accumulation Mode ◽  
Measurement Results ◽  
Aitken Mode

Abstract. Atmospheric aerosol particles serving as cloud condensation nuclei (CCN) are key elements of the hydrological cycle and climate. We have measured and characterized CCN at water vapor supersaturations in the range of S=0.10–0.82% in pristine tropical rainforest air during the AMAZE-08 campaign in central Amazonia. The effective hygroscopicity parameters describing the influence of chemical composition on the CCN activity of aerosol particles varied in the range of κ=0.05–0.45. The overall median value of κ≈0.15 was only half of the value typically observed for continental aerosols in other regions of the world. Aitken mode particles were less hygroscopic than accumulation mode particles (κ≈0.1 at D≈50 nm; κ≈0.2 at D≈200 nm). The CCN measurement results were fully consistent with aerosol mass spectrometry (AMS) data, which showed that the organic mass fraction (Xm,org) was on average as high as ~90% in the Aitken mode (D≤100 nm) and decreased with increasing particle diameter in the accumulation mode (~80% at D≈200 nm). The κ values exhibited a close linear correlation with Xm,org and extrapolation yielded the following effective hygroscopicity parameters for organic and inorganic particle components: κorg≈0.1 which is consistent with laboratory measurements of secondary organic aerosols and κinorg≈0.6 which is characteristic for ammonium sulfate and related salts. Both the size-dependence and the temporal variability of effective particle hygroscopicity could be parameterized as a function of AMS-based organic and inorganic mass fractions (κp=0.1 Xm,org+0.6 Xm,inorg), and the CCN number concentrations predicted with κp were in fair agreement with the measurement results. The median CCN number concentrations at S=0.1–0.82% ranged from NCCN,0.10≈30 cm−3 to NCCN,0.82≈150 cm−3, the median concentration of aerosol particles larger than 30 nm was NCN,30≈180 cm−3, and the corresponding integral CCN efficiencies were in the range of NCCN,0.10/NCN,30≈0.1 to NCCN,0.82/NCN,30≈0.8. Although the number concentrations and hygroscopicity parameters were much lower, the integral CCN efficiencies observed in pristine rainforest air were similar to those in highly polluted mega-city air. Moreover, model calculations of NCCN,S with a global average value of κ=0.3 led to systematic overpredictions, but the relative deviations exceeded ~50% only at low water vapor supersaturation (0.1%) and low particle number concentrations (≤100 cm−3). These findings confirm earlier studies suggesting that aerosol particle number and size are the major predictors for the variability of the CCN concentration in continental boundary layer air, followed by particle composition and hygroscopicity as relatively minor modulators. Depending on the required and applicable level of detail, the information and parameterizations presented in this paper should enable efficient description of the CCN properties of pristine tropical rainforest aerosols in detailed process models as well as in large-scale atmospheric and climate models.

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