| Autor: |
Vlasenko, Sergey S., Hang Su, Pöschl, Ulrich, Andreae, Meinrat O., Mikhailov, Eugene F. |
| Předmět: |
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| Zdroj: |
Atmospheric Measurement Techniques Discussions; 2016, p1-23, 23p |
| Abstrakt: |
A tandem arrangement of Differential Mobility Analyzer and Humidified Centrifugal Particle Mass Analyzer (DMA-HCPMA) was developed to measure the deliquescence and efflorescence thresholds and the water uptake of submicron particles over the relative humidity (RH) range from 10 % to 95 %. The hygroscopic growth curves obtained for Ammonium sulfate and sodium chloride test aerosols are consistent with thermodynamic model predictions and literature data. The DMA-HCPMA system was applied to measure the hygroscopic properties of urban aerosol particles, and the kappa mass interaction model (KIM) was used to characterize and parameterize the concentration-dependent water uptake observed in the 50-95 % RH range. For DMA-selected 160 nm dry particles (mass of 3.5 fg), we obtained a volume-based hygroscopicity parameter Kv ≈ 0.2, which is consistent with literature data for freshly emitted urban aerosols. Overall, our results show that the DMA-HCPMA system can be used to measure size-resolved mass growth factors of atmospheric aerosol particles upon hydration and dehydration up to 95 % RH. The direct measurements of humidified particle mass allow avoiding complications that occur in the commonly used mobility-diameter-based HTDMA technique due to poorly defined particle morphology and density. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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