| Autor: |
Järvinen, Emma, Ignatius, Karoliina, Nichman, Leonid, Kristensen, Thomas B., Fuchs, Claudia, Hoyle, Christopher R., Höppel, Niko, Corbin, Joel C., Craven, Jill, Duplissy, Jonathan, Ehrhart, Sebastian, El Haddad, Imad, Frege, Carla, Gordon, Hamish, Jokinen, Tuija, Kallinger, Peter, Kirkby, Jasper, Kiselev, Alexei, Naumann, Karl-Heinz, Petäjä, Tuukka |
| Předmět: |
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| Zdroj: |
Atmospheric Chemistry & Physics; 2016, Vol. 16 Issue 7, p4423-4438, 16p, 3 Diagrams, 1 Chart, 8 Graphs |
| Abstrakt: |
European Organisation for Nuclear Research (CERN), we deployed a new in situ optical method to detect the viscous state ofα-pinene SOA particles and measured their transition from the amorphous highly viscous state to states of lower viscosity. The method is based on the depolarising properties of laboratory-produced non-spherical SOA particles and their transformation to non-depolarising spherical particles at relative humidities near the deliquescence point. We found that particles formed and grown in the chamber developed an asymmetric shape through coagulation. A transition to a spherical shape was observed as the RH was increased to between 35% at--10°C and 80% at--38°C, confirming previous calculations of the viscositytransition conditions. Consequently,α-pinene SOA particles exist in a viscous state over a wide range of ambient conditions, including the cirrus region of the free troposphere. This has implications for the physical, chemical, and icenucleation properties of SOA and SOA-coated particles in the atmosphere. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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