CCN activity of organic aerosols observed downwind of urban emissions during CARES
نویسندگان
چکیده
100 to 171 nm, derived from the size-resolved activated fraction, varied from 0.10 to 0.21, with an average of 0.15, which was substantially lower than that proposed for continental sites in earlier studies. The low κCCN value was due to the high organic volume fraction, averaged over 80% at the T1 site. The derived κCCN exhibited little diurnal variation, consistent with the relatively constant organic volume fraction observed. 10
منابع مشابه
Supplement of CCN activity and organic hygroscopicity of aerosols downwind of an urban region in central Amazonia: seasonal and diel variations and impact of anthropogenic emissions
متن کامل
Interactive comment on “CCN activity and organic hygroscopicity of aerosols downwind of an urban region in central Amazonia: Seasonal and diel variations and impact of anthropogenic emissions” by Ryan Thalman et al
Study by Thalman et al. presents results of κCCN and mixing state derived from sizeresolved CCN observations collected during the GoAmazon2014/5 campaign. From κCCN and additinal aerosol chemical composition measurements, the authors then estimate the hygroscopicity of the organic fraction κorg. The results presented in the study, together with those presented by Pöhlker et al (2016) in another...
متن کاملEvolution of Multispectral Aerosol Absorption Properties in a Biogenically-Influenced Urban Environment during the CARES Campaign
We present the evolution of multispectral optical properties through urban aerosols that have aged and interacted with biogenic emissions, resulting in stronger short wavelength absorption and the formation of moderately brown secondary organic aerosols. Ground-based aerosol measurements were made in June 2010 within the Sacramento urban area (site T0) and at a 40-km downwind location (site T1)...
متن کاملCCN predictions on particles containing mixed organic and elemental carbon using Köhler theory
Anthropogenic atmospheric aerosols play a large role in climate change by acting as cloud condensation nuclei (CCN) and influencing cloud reflectivity. The ability of anthropogenic aerosols to contribute to cloud droplet activation depends on particle size and composition. Up to 90% of fine particle mass (PM2.5) is composed of carbonaceous (elemental and organic carbon) compounds, which play a ...
متن کاملContributions of organic and sulfate components to CCN concentrations in a boreal forest
The ability of atmospheric aerosols to nucleate cloud droplets is dependent on both the particle size and composition. Organic compounds significantly contribute to particle composition; thus, their ability to act as cloud condensation nuclei (CCN) is crucial for understanding cloud droplet formation. While the organic fraction can significantly alter the hygroscopicity of particles, the comple...
متن کامل