Cloud condensation nuclei measurements in the marine boundary layer of the Eastern Mediterranean: CCN closure and droplet growth kinetics

Bougiatioti, A.; Fountoukis, C.; Kalivitis, N.; Pandis, Spyros N.; Nenes, Athanasios; Mihalopoulos, Nikos

doi:10.5194/acp-9-7053-2009

Cited by 156 publications

(180 citation statements)

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“…In the case of Mace Head, the observed behaviour is due to the presence of sea salt particles and a peculiar organic composition of the marine aerosol (Ovadnevaite et al, 2011). Additionally, both Finokalia and Mace Head have a large fraction of the long-range transported and aged aerosol (Bougiatioti et al, 2009;Ovadnevaite et al, 2011), which has Also shown is the overall fit based on most of the data points (*Finokalia, COPS, Jungfraujoch and Pallas A, B and C data sets excluded). The shading of the overall fit represents the prediction bounds of the fit with a confidence level of 95 %.…”

Section: Ccn Concentrationsmentioning

confidence: 97%

A synthesis of cloud condensation nuclei counter (CCNC) measurements within the EUCAARI network

et al. 2015

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Published by Copernicus Publications on behalf of the European Geosciences Union. M. Paramonov et al.: A synthesis of CCNC measurements within the EUCAARI networkAbstract. Cloud condensation nuclei counter (CCNC) measurements performed at 14 locations around the world within the European Integrated project on Aerosol Cloud Climate and Air Quality interactions (EUCAARI) framework have been analysed and discussed with respect to the cloud condensation nuclei (CCN) activation and hygroscopic properties of the atmospheric aerosol. The annual mean ratio of activated cloud condensation nuclei (N CCN ) to the total number concentration of particles (N CN ), known as the activated fraction A, shows a similar functional dependence on supersaturation S at many locations -exceptions to this being certain marine locations, a free troposphere site and background sites in south-west Germany and northern Finland. The use of total number concentration of particles above 50 and 100 nm diameter when calculating the activated fractions (A 50 and A 100 , respectively) renders a much more stable dependence of A on S; A 50 and A 100 also reveal the effect of the size distribution on CCN activation. With respect to chemical composition, it was found that the hygroscopicity of aerosol particles as a function of size differs among locations. The hygroscopicity parameter κ decreased with an increasing size at a continental site in south-west Germany and fluctuated without any particular size dependence across the observed size range in the remote tropical North Atlantic and rural central Hungary. At all other locations κ increased with size. In fact, in Hyytiälä, Vavihill, Jungfraujoch and Pallas the difference in hygroscopicity between Aitken and accumulation mode aerosol was statistically significant at the 5 % significance level. In a boreal environment the assumption of a size-independent κ can lead to a potentially substantial overestimation of N CCN at S levels above 0.6 %. The same is true for other locations where κ was found to increase with size. While detailed information about aerosol hygroscopicity can significantly improve the prediction of N CCN , total aerosol number concentration and aerosol size distribution remain more important parameters. The seasonal and diurnal patterns of CCN activation and hygroscopic properties vary among three long-term locations, highlighting the spatial and temporal variability of potential aerosol-cloud interactions in various environments.

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Section: Ccn Concentrationsmentioning

confidence: 97%

A synthesis of cloud condensation nuclei counter (CCNC) measurements within the EUCAARI network

et al. 2015

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“…To account for hygroscopicity and dry size differences between aerosol, both droplet sizes are selected from the point where activation is first observed. TDGA has been applied to several ambient aerosol samples (AsaAwuku et al, 2011;Bougiatioti et al, 2009Bougiatioti et al, , 2011Lance et al, 2009;Murphy et al, 2009;Padró et al, 2010Padró et al, , 2011Cerully et al, 2011), secondary organic aerosol (SOA) (Engelhart et al, 2008(Engelhart et al, , 2011Asa-Awuku et al, 2009 and laboratory-generated aerosol (Moore et al, 2008;Kumar et al, 2011a,b). In general, slower kinetics than calibration aerosol have been related to insoluble organics from SOA chamber experiments (Asa-Awuku et al, 2009), fresh exhaust plumes , and mineral dust particles when using a dry generation technique (Kumar et al, 2011a,b).…”

Section: T Raatikainen Et Al: Activation Kinetics From Measurementsmentioning

confidence: 99%

A coupled observation – modeling approach for studying activation kinetics from measurements of CCN activity

et al. 2012

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Abstract. This paper presents an approach to study droplet activation kinetics from measurements of CCN activity by the Continuous Flow Streamwise Thermal Gradient CCN Chamber (CFSTGC) and a comprehensive model of the instrument and droplet growth. The model, which can be downloaded from http://nenes.eas.gatech.edu/Experiments/ CFSTGC.html, is evaluated against a series of experiments with ammonium sulfate calibration aerosol. Observed and modeled droplet sizes are in excellent agreement for a water vapor uptake coefficient ∼0.2, which is consistent with theoretical expectations. The model calculations can be considerably accelerated without significant loss of accuracy by assuming simplified instrument geometry and constant parabolic flow velocity profiles. With these assumptions, the model can be applied to large experimental data sets to infer kinetic growth parameters while fully accounting for water vapor depletion effects and changes in instrument operation parameters such as the column temperature, flow rates, sheath and sample flow relative humidities, and pressure. When the effects of instrument operation parameters, water vapor depletion and equilibrium dry particle properties on droplet size are accounted for, the remaining variations in droplet size are most likely due to non-equilibrium processes such as those caused by organic surface films, slow solute dissociation and glassy or highly viscous particle states. As an example of model application, data collected during a research flight in the ARCTAS 2008 campaign are analyzed. The model shows that water vapor depletion effects can explain changes in the observed average droplet size.

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“…These values for activated fraction compare well to observations of, presumably, aged continental aerosols collected by Gunthe et al (2009) in the Amazon rain forest. In contrast, Bougiatioti et al (2009) found activated fraction values well above 0.5 even at SS = 0.4 %. They sampled at a marine location where the aerosol is likely to be larger and consist principally of sea-salt.…”

Section: Mesa Verde Resultsmentioning

confidence: 65%

“…Recent attempts have focused on measuring aerosol composition as the key to achieving CCN closure (Ervens et al, 2007;Quinn et al, 2008;Furutani et al, 2008;Bougiatioti et al, 2009). Broekhuizen et al (2006) and Cubison et al (2008) both show evidence that CCN closure can be improved with knowledge of size-dependent composition.…”

Section: Ccn Closure Reviewmentioning

confidence: 99%

“…VanReken et al, 2003;Medina et al, 2007;Quinn et al, 2008;Furutani et al, 2008;Bougiatioti et al, 2009). Traditionally these distinctions are made using trajectory analysis and are often limited to labeling observations as marine-source or continental-source, as in VanReken et al (2003), Furutani et al (2008), and Bougiatioti et al (2009).…”

Section: Aerosol and Geopotential Height Regression Analysismentioning

confidence: 99%

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Cold and transition season cloud condensation nuclei measurements in western Colorado

Ward

Cotton

2011

Atmos. Chem. Phys.

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Abstract.Recent studies have shown that orographic precipitation and the water resources that depend on it in the Colorado Rocky Mountains are sensitive to the variability of the region's aerosols, whether emitted locally or from distant sources. However, observations of cloud droplet nucleating aerosols in western Colorado, climatologically upwind of the Colorado Rocky Mountains, have been limited to a few studies at a single, northern site. To address this knowledge gap, atmospheric aerosols were sampled at a ground site in southwestern Colorado and in low-level north to south transects of the Colorado Western Slope as part of the Inhibition of Snowfall by Pollution Aerosols (ISPA-III) field campaign. Total particle and cloud condensation nuclei (CCN) number concentrations were measured for a 24-day period in Mesa Verde National Park, in September and October 2009. Regression analysis showed a positive relationship between mid-troposphere atmospheric pressure to the west of the site and the total particle count at the ground site, but no similar statistically significant relationship was found for the observed CCN. These data were supplemented with particle and CCN number concentration, as well as particle size distribution measurements collected aboard the King Air platform during December 2009. A CCN closure attempt was performed and suggested that the sampled aerosol may have had a low hygroscopicity that changed little with the largescale wind direction. Together, the sampled aerosols from these field programs were characteristic of a rural continental environment with CCN number concentrations that varied slowly in time, and little in space along the Western Slope.

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Cloud condensation nuclei measurements in the marine boundary layer of the Eastern Mediterranean: CCN closure and droplet growth kinetics

Cited by 156 publications

References 81 publications

A synthesis of cloud condensation nuclei counter (CCNC) measurements within the EUCAARI network

A synthesis of cloud condensation nuclei counter (CCNC) measurements within the EUCAARI network

A coupled observation – modeling approach for studying activation kinetics from measurements of CCN activity

Cold and transition season cloud condensation nuclei measurements in western Colorado

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