Towards a bulk approach to local interactions of hydrometeors
The growth of small cloud droplets and ice crystals is dominated by the diffusion of water vapor. Usually, Maxwell's approach to growth for isolated particles is used in describing this process. However, recent investigations show that local interactions between particles can change diffusi...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-02-01
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| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/18/2525/2018/acp-18-2525-2018.pdf |
| Summary: | The growth
of small cloud droplets and ice crystals is dominated by the diffusion of
water vapor. Usually, Maxwell's approach to growth for isolated particles is
used in describing this process. However, recent investigations show that
local interactions between particles can change diffusion properties of cloud
particles. In this study we develop an approach for including these local
interactions into a bulk model approach. For this purpose, a simplified
framework of local interaction is proposed and governing equations are
derived from this setup. The new model is tested against direct simulations
and incorporated into a parcel model framework. Using the parcel model,
possible implications of the new model approach for clouds are investigated.
The results indicate that for specific scenarios the lifetime of cloud
droplets in subsaturated air may be longer (e.g., for an initially water
supersaturated air parcel within a downdraft). These effects might have an
impact on mixed-phase clouds, for example in terms of riming efficiencies. |
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| ISSN: | 1680-7316 1680-7324 |