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Ice multiplication by breakup in ice-ice collisions. Part II : Numerical simulations

Phillips, Vaughan T.J. LU ; Yano, Jun-Ichi; Formenton, Marco LU ; Ilotoviz, Eyal; Kanawade, Vijay LU ; Kudzotsa, Innocent LU ; Sun, Jiming; Bansemer, Aaron; Detwiler, Andrew G. and Khain, Alexander, et al. (2017) In Journals of the Atmospheric Sciences 74(9). p.2789-2811
Abstract

In Part I of this two-part paper, a formulation was developed to treat fragmentation in ice-ice collisions. In the present Part II, the formulation is implemented in two microphysically advanced cloud models simulating a convective line observed over the U.S. high plains. One model is 2D with a spectral bin microphysics scheme. The other has a hybrid bin-two-moment bulk microphysics scheme in 3D. The case consists of cumulonimbus cells with cold cloud bases (near 0° C) in a dry troposphere. Only with breakup included in the simulation are aircraft observations of particles with maximum dimensions >0.2mmin the storm adequately predicted by both models. In fact, breakup in ice-ice collisions is by far the most prolific process of ice... (More)

In Part I of this two-part paper, a formulation was developed to treat fragmentation in ice-ice collisions. In the present Part II, the formulation is implemented in two microphysically advanced cloud models simulating a convective line observed over the U.S. high plains. One model is 2D with a spectral bin microphysics scheme. The other has a hybrid bin-two-moment bulk microphysics scheme in 3D. The case consists of cumulonimbus cells with cold cloud bases (near 0° C) in a dry troposphere. Only with breakup included in the simulation are aircraft observations of particles with maximum dimensions >0.2mmin the storm adequately predicted by both models. In fact, breakup in ice-ice collisions is by far the most prolific process of ice initiation in the simulated clouds (95%-98% of all nonhomogeneous ice), apart from homogeneous freezing of droplets. Inclusion of breakup in the cloud-resolving model (CRM) simulations increased, by between about one and two orders of magnitude, the average concentration of ice between about 0° and -30°C. Most of the breakup is due to collisions of snow with graupel/hail. It is broadly consistent with the theoretical result in Part I about an explosive tendency for ice multiplication. Breakup in collisions of snow (crystals > ~1mm and aggregates) with denser graupel/hail was the main pathway for collisional breakup and initiated about 60%-90% of all ice particles not from homogeneous freezing, in the simulations by both models. Breakup is predicted to reduce accumulated surface precipitation in the simulated storm by about 20%-40%.

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publication status
published
subject
keywords
Cloud microphysics, Clouds, Hail, Ice particles
in
Journals of the Atmospheric Sciences
volume
74
issue
9
pages
23 pages
publisher
Amer Meteorological Soc
external identifiers
  • scopus:85029043360
  • wos:000409847100005
ISSN
0022-4928
DOI
10.1175/JAS-D-16-0223.1
language
English
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yes
id
e5f99def-6cc5-4220-a2b5-93057a0014de
date added to LUP
2017-09-26 13:43:19
date last changed
2018-01-16 13:26:51
@article{e5f99def-6cc5-4220-a2b5-93057a0014de,
  abstract     = {<p>In Part I of this two-part paper, a formulation was developed to treat fragmentation in ice-ice collisions. In the present Part II, the formulation is implemented in two microphysically advanced cloud models simulating a convective line observed over the U.S. high plains. One model is 2D with a spectral bin microphysics scheme. The other has a hybrid bin-two-moment bulk microphysics scheme in 3D. The case consists of cumulonimbus cells with cold cloud bases (near 0° C) in a dry troposphere. Only with breakup included in the simulation are aircraft observations of particles with maximum dimensions &gt;0.2mmin the storm adequately predicted by both models. In fact, breakup in ice-ice collisions is by far the most prolific process of ice initiation in the simulated clouds (95%-98% of all nonhomogeneous ice), apart from homogeneous freezing of droplets. Inclusion of breakup in the cloud-resolving model (CRM) simulations increased, by between about one and two orders of magnitude, the average concentration of ice between about 0° and -30°C. Most of the breakup is due to collisions of snow with graupel/hail. It is broadly consistent with the theoretical result in Part I about an explosive tendency for ice multiplication. Breakup in collisions of snow (crystals &gt; ~1mm and aggregates) with denser graupel/hail was the main pathway for collisional breakup and initiated about 60%-90% of all ice particles not from homogeneous freezing, in the simulations by both models. Breakup is predicted to reduce accumulated surface precipitation in the simulated storm by about 20%-40%. </p>},
  author       = {Phillips, Vaughan T.J. and Yano, Jun-Ichi and Formenton, Marco and Ilotoviz, Eyal and Kanawade, Vijay and Kudzotsa, Innocent and Sun, Jiming and Bansemer, Aaron and Detwiler, Andrew G. and Khain, Alexander and Tessendorf, Sarah A.},
  issn         = {0022-4928},
  keyword      = {Cloud microphysics,Clouds,Hail,Ice particles},
  language     = {eng},
  month        = {09},
  number       = {9},
  pages        = {2789--2811},
  publisher    = {Amer Meteorological Soc},
  series       = {Journals of the Atmospheric Sciences},
  title        = {Ice multiplication by breakup in ice-ice collisions. Part II : Numerical simulations},
  url          = {http://dx.doi.org/10.1175/JAS-D-16-0223.1},
  volume       = {74},
  year         = {2017},
}