Ice-Ice Collisions: An Ice Multiplication Process in Atmospheric Clouds
Yano, J. -I. and Phillips, Vaughan LU
(2011)
In Journal of Atmospheric Sciences
68(2).
p.322-333
- Abstract
- Ice in atmospheric clouds undergoes complex physical processes, interacting especially with radiation, which leads to serious impacts on global climate. After their primary production, atmospheric ice crystals multiply extensively by secondary processes. Here, it is shown that a mostly overlooked process of mechanical breakup of ice particles by ice-ice collisions contributes to such observed multiplication. A regime for explosive multiplication is identified in its phase space of ice multiplication efficiency and number concentration of ice particles. Many natural mixed-phase clouds, if they have copious millimeter-sized graupel, fall into this explosive regime. The usual Hallett-Mossop (H-M) process of ice multiplication is shown to... (More)
- Ice in atmospheric clouds undergoes complex physical processes, interacting especially with radiation, which leads to serious impacts on global climate. After their primary production, atmospheric ice crystals multiply extensively by secondary processes. Here, it is shown that a mostly overlooked process of mechanical breakup of ice particles by ice-ice collisions contributes to such observed multiplication. A regime for explosive multiplication is identified in its phase space of ice multiplication efficiency and number concentration of ice particles. Many natural mixed-phase clouds, if they have copious millimeter-sized graupel, fall into this explosive regime. The usual Hallett-Mossop (H-M) process of ice multiplication is shown to dominate the overall ice multiplication when active, as it starts sooner, compared to the breakup ice multiplication process. However, for deep clouds with a cold base temperature where the usual H-M process is inactive, the ice breakup mechanism should play a critical role. Supercooled rain, which may freeze to form graupel directly in only a few minutes, is shown to hasten such ice multiplication by mechanical breakup, with an ice enhancement ratio exceeding 10(4) approximately 20 min after small graupel first appear. The ascent-dependent onset of subsaturation with respect to liquid water during explosive ice multiplication is predicted to determine the eventual ice concentrations. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/4587455
- author
- Yano, J. -I.
and Phillips, Vaughan
LU
- publishing date
- 2011
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Atmospheric Sciences
- volume
- 68
- issue
- 2
- pages
- 322 - 333
- publisher
- Amer Meteorological Soc
- external identifiers
-
- wos:000288144300009
- scopus:79953188395
- ISSN
- 1520-0469
- DOI
- 10.1175/2010JAS3607.1
- language
- English
- LU publication?
- no
- id
- 5d29a87f-7503-416d-9bb6-38d24a3c6a1b (old id 4587455)
- date added to LUP
- 2016-04-01 10:40:30
- date last changed
- 2022-04-04 20:11:13
@article{5d29a87f-7503-416d-9bb6-38d24a3c6a1b,
abstract = {{Ice in atmospheric clouds undergoes complex physical processes, interacting especially with radiation, which leads to serious impacts on global climate. After their primary production, atmospheric ice crystals multiply extensively by secondary processes. Here, it is shown that a mostly overlooked process of mechanical breakup of ice particles by ice-ice collisions contributes to such observed multiplication. A regime for explosive multiplication is identified in its phase space of ice multiplication efficiency and number concentration of ice particles. Many natural mixed-phase clouds, if they have copious millimeter-sized graupel, fall into this explosive regime. The usual Hallett-Mossop (H-M) process of ice multiplication is shown to dominate the overall ice multiplication when active, as it starts sooner, compared to the breakup ice multiplication process. However, for deep clouds with a cold base temperature where the usual H-M process is inactive, the ice breakup mechanism should play a critical role. Supercooled rain, which may freeze to form graupel directly in only a few minutes, is shown to hasten such ice multiplication by mechanical breakup, with an ice enhancement ratio exceeding 10(4) approximately 20 min after small graupel first appear. The ascent-dependent onset of subsaturation with respect to liquid water during explosive ice multiplication is predicted to determine the eventual ice concentrations.}},
author = {{Yano, J. -I. and Phillips, Vaughan}},
issn = {{1520-0469}},
language = {{eng}},
number = {{2}},
pages = {{322--333}},
publisher = {{Amer Meteorological Soc}},
series = {{Journal of Atmospheric Sciences}},
title = {{Ice-Ice Collisions: An Ice Multiplication Process in Atmospheric Clouds}},
url = {{http://dx.doi.org/10.1175/2010JAS3607.1}},
doi = {{10.1175/2010JAS3607.1}},
volume = {{68}},
year = {{2011}},
}