Ice nucleation properties of volcanic ash from Eyjafjallajökull ...
The ice nucleation ability of volcanic ash particles collected close to the Icelandic volcano Eyjafjallajökull during its eruptions in April and May 2010 is investigated experimentally, in the immersion and deposition modes, and applied to atmospheric conditions by comparison with airborne measureme...
| Main Authors: | , , , , , , , , , , , |
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| Format: | Text |
| Language: | English |
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ETH Zurich
2011
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| Subjects: | |
| Online Access: | https://dx.doi.org/10.3929/ethz-b-000160104 http://hdl.handle.net/20.500.11850/160104 |
| Summary: | The ice nucleation ability of volcanic ash particles collected close to the Icelandic volcano Eyjafjallajökull during its eruptions in April and May 2010 is investigated experimentally, in the immersion and deposition modes, and applied to atmospheric conditions by comparison with airborne measurements and microphysical model calculations. The number of ash particles which are active as ice nuclei (IN) is strongly temperature dependent, with a very small minority being active in the immersion mode at temperatures of 250–263 K. Average ash particles show only a moderate effect on ice nucleation, by inducing freezing at temperatures between 236 K and 240 K (i.e. approximately 3–4 K higher than temperatures required for homogeneous ice nucleation, measured with the same instrument). By scaling the results to aircraft and lidar measurements of the conditions in the ash plume days down wind of the eruption, and by applying a simple microphysical model, it was found that the IN active in the immersion mode in the ... : Atmospheric Chemistry and Physics, 11 (18) ... |
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