Nucleation of nitric acid hydrates in polar stratospheric clouds by meteoric material
Heterogeneous nucleation of crystalline nitric acid hydrates in polar stratospheric clouds (PSCs) enhances ozone depletion. However, the identity and mode of action of the particles responsible for nucleation remains unknown. It has been suggested that meteoric material may trigger nucleation of...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-04-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/4519/2018/acp-18-4519-2018.pdf |
| Summary: | Heterogeneous nucleation of crystalline nitric acid hydrates in
polar stratospheric clouds (PSCs) enhances ozone depletion. However, the
identity and mode of action of the particles responsible for nucleation
remains unknown. It has been suggested that meteoric material may trigger
nucleation of nitric acid trihydrate (NAT, or other nitric acid phases), but
this has never been quantitatively demonstrated in the laboratory. Meteoric
material is present in two forms in the stratosphere: smoke that results
from the ablation and re-condensation of vapours, and fragments that result
from the break-up of meteoroids entering the atmosphere. Here we show that
analogues of both materials have a capacity to nucleate nitric acid hydrates.
In combination with estimates from a global model of the amount of meteoric
smoke and fragments in the polar stratosphere we show that meteoric material
probably accounts for NAT observations in early season polar stratospheric
clouds in the absence of water ice. |
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| ISSN: | 1680-7316 1680-7324 |