CCN Ability of Asian Mineral Dust Particles and Their Effects on Cloud Droplet Formation

Yamashita, Kazuya; Murakami, Masataka; Hashimoto, Akihiro; Tajiri, Takeyoshi

doi:10.2151/jmsj.2011-512

Cited by 24 publications

(27 citation statements)

References 29 publications

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“…The ratios of number concentrations of CCN and condensation nuclei (CN), Nccn/Ncn, were 0.2 at SSw = 0.1%, 0.5 at SSw = 0.2%, and 1.0 at SSw = 0.8%. These results are consistent with the size resolved CCN measurements of ATD by Koehler et al (2009) and Yamashita et al (2011). The ATD particles by themselves may effectively act as CCN if there are no hygroscopic particles that act as CCN more efficiently than ATD particles (Yamashita et al 2011).…”

Section: Cold Cloud In Activation Experimentssupporting

confidence: 88%

“…These results are consistent with the size resolved CCN measurements of ATD by Koehler et al (2009) and Yamashita et al (2011). The ATD particles by themselves may effectively act as CCN if there are no hygroscopic particles that act as CCN more efficiently than ATD particles (Yamashita et al 2011). The ATD particles appear to be better CCN than ammonium sulfate, but this is because of their larger sizes.…”

Section: Cold Cloud In Activation Experimentssupporting

confidence: 88%

“…The slight deviation from zero is due to an incomplete linear polarization of the laser light and minor misalignments of the polarizers in the optical setup. Relative humidity with respect to water and number concentrations of particles larger than 2 μm simulated with a detailed bin microphysics parcel model (Yamashita et al 2011) are also shown in the panels (c), (d), and (e). The measured concentrations of activated droplets agreed well with those simulated by the detailed bin microphysics parcel model, which is based on the parcel model of Chen and Lamb (1994) an ascent velocity of 3 m s −1 and initial values of air temperature, humidity, air pressure, aerosol size distribution, and their hygroscopicity based on the expansion experiment.…”

Section: Warm Cloud Ccn Activation Experimentsmentioning

confidence: 99%

See 2 more Smart Citations

A Novel Adiabatic-Expansion-Type Cloud Simulation Chamber

Tajiri¹,

Yamashita²,

Murakami³

et al. 2013

Journal of the Meteorological Society of Japan

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A new cloud simulation chamber was built at the Meteorological Research Institute (MRI) to investigate the details of the fundamental processes of cloud formation. The MRI cloud chamber was designed as an adiabatic-expansiontype cloud chamber covering temperatures from 30 to −100°C, pressures from 1030 to 30 hPa, and an evacuation rates corresponding to ascent rates from 0 to 30 m s −1. Improvements to the cooling system and cloud characterization instrumentation distinguish the new facility from past devices of this type that are no longer functional (e.g., the Colorado State University dynamic cloud chamber), and the capabilities exceed those of any other active facility (e.g., the Aerosol Interactions and Dynamics in the Atmosphere (AIDA) chamber) for covering a range of atmospheric conditions while reproducing approximately adiabatic parcel conditions. Results from the preliminary experiments demonstrate the accuracy of coordinated pressure and temperature controls to reproduce cloud formation processes (both dry and wet adiabatic expansion processes) and the ability of the chamberʼs instrumentation to measure aerosol, cloud droplet, and ice crystal characteristics. Performance tests demonstrate the chamberʼs usefulness as a facility to investigate cloud droplet and ice crystal formation processes through the activation of various types of aerosol particles.

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Section: Cold Cloud In Activation Experimentssupporting

confidence: 88%

Section: Cold Cloud In Activation Experimentssupporting

confidence: 88%

Section: Warm Cloud Ccn Activation Experimentsmentioning

confidence: 99%

See 1 more Smart Citation

A Novel Adiabatic-Expansion-Type Cloud Simulation Chamber

Tajiri¹,

Yamashita²,

Murakami³

et al. 2013

Journal of the Meteorological Society of Japan

Self Cite

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“…Studies have shown that κ of more oxidized secondary organic species can be as high as 0.22 (Chang et al, 2010), although Frosch et al (2011) found no relationship between κ and O / C ratio for α-pinene SOA aged in a smog chamber. Black carbon and dust are typically measured or assumed to have κ values of ∼0-0.05 (Koehler et al, 2009;Yamashita et al, 2011). As a representative average value for the fine mode aerosol that dominates CCN number concentrations, continental aerosol particles are often assumed to be adequately represented by a hygroscopicity parameter of ∼0.3 Pringle et al, 2010;Pöschl et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Size-resolved aerosol composition and its link to hygroscopicity at a forested site in Colorado

et al. 2014

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Abstract. Aerosol hygroscopicity describes the ability of a particle to take up water and form a cloud droplet. Modeling studies have shown sensitivity of precipitation-producing cloud systems to the availability of aerosol particles capable of serving as cloud condensation nuclei (CCN), and hygroscopicity is a key parameter controlling the number of available CCN. Continental aerosol is typically assumed to have a representative hygroscopicity parameter, κ, of 0.3; however, in remote locations this value can be lower due to relatively large mass fractions of organic components. To further our understanding of aerosol properties in remote areas, we measured size-resolved aerosol chemical composition and hygroscopicity in a forested, mountainous site in Colorado during the six-week BEACHON-RoMBAS (Bio-hydro-atmosphere interactions of Energy, Aerosols, Carbon, H 2 O, Organics and Nitrogen-Rocky Mountain Biogenic Aerosol Study) campaign. This campaign followed a year-long measurement period at this site, and results from the intensive campaign shed light on the previously reported seasonal cycle in aerosol hygroscopicity. New particle formation events were observed routinely at this site and nucleation mode composition measurements indicated that the newly formed particles were predominantly organic. These events likely contribute to the dominance of organic species at smaller sizes, where aerosol organic mass fractions were between 70 and 90 %. Corresponding aerosol hygroscopicity was observed to be in the range κ = 0.15-0.22, with hygroscopicity increasing with particle size. Aerosol chemical composition measured by an aerosol mass spectrometer and calculated from hygroscopicity measurements agreed very well during the intensive study, with an assumed value of κ org = 0.13 resulting in the best agreement.

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“…Bègue et al (2015) analyzed a case of possible mixing of European pollution aerosols with Saharan dust transported over northern Europe, and found that aged Saharan dust was sufficiently soluble to impact the hygroscopic growth and cloud droplet activation over the Netherlands. Asian dust has also been reported to have a considerable impact on cloud formation after being transported over long distances and mixed with soluble materials (Perry et al, 2004;Roberts et al, 2006;Sullivan et al, 2007;Ma et al, 2010;Stone et al, 2011;Yamashita et al, 2011).…”

mentioning

confidence: 99%

Global impact of mineral dust on cloud droplet number concentration

et al. 2017

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Abstract. The importance of wind-blown mineral dust for cloud droplet formation is studied by considering (i) the adsorption of water on the surface of insoluble particles, (ii) particle coating by soluble material (atmospheric aging) which augments cloud condensation nuclei (CCN) activity, and (iii) the effect of dust on inorganic aerosol concentrations through thermodynamic interactions with mineral cations. The ECHAM5/MESSy Atmospheric Chemistry (EMAC) model is used to simulate the composition of global atmospheric aerosol, while the ISORROPIA-II thermodynamic equilibrium model treats the interactions of K + -Ca 2+ -Mg 2+ -NHaerosol with gas-phase inorganic constituents. Dust is considered a mixture of inert material with reactive minerals and its emissions are calculated online by taking into account the soil particle size distribution and chemical composition of different deserts worldwide. The impact of dust on droplet formation is treated through the "unified dust activation parameterization" that considers the inherent hydrophilicity from adsorption and acquired hygroscopicity from soluble salts during aging. Our simulations suggest that the presence of dust increases cloud droplet number concentration (CDNC) over major deserts (e.g., up to 20 % over the Sahara and the Taklimakan desert) and decreases CDNC over polluted areas (e.g., up to 10 % over southern Europe and 20 % over northeastern Asia). This leads to a global net decrease in CDNC by 11 %. The adsorption activation of insoluble aerosols and the mineral dust chemistry are shown to be equally important for the cloud droplet formation over the main deserts; for example, these effects increase CDNC by 20 % over the Sahara. Remote from deserts the application of adsorption theory is critically important since the increased water uptake by the large aged dust particles (i.e., due to the added hydrophilicity by the soluble coating) reduce the maximum supersaturation and thus cloud droplet formation from the relatively smaller anthropogenic particles (e.g., CDNC decreases by 10 % over southern Europe and 20 % over northeastern Asia by applying adsorption theory). The global average CDNC decreases by 10 % by considering adsorption activation, while changes are negligible when accounting for the mineral dust chemistry. Sensitivity simulations indicate that CDNC is also sensitive to the mineral dust mass and inherent hydrophilicity, and not to the chemical composition of the emitted dust.

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CCN Ability of Asian Mineral Dust Particles and Their Effects on Cloud Droplet Formation

Cited by 24 publications

References 29 publications

A Novel Adiabatic-Expansion-Type Cloud Simulation Chamber

A Novel Adiabatic-Expansion-Type Cloud Simulation Chamber

Size-resolved aerosol composition and its link to hygroscopicity at a forested site in Colorado

Global impact of mineral dust on cloud droplet number concentration

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