Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Default user image.

Vaughan Phillips

Universitetslektor

Default user image.

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

Författare

  • Vaughan T.J. Phillips
  • Jun-Ichi Yano
  • Marco Formenton
  • Eyal Ilotoviz
  • Vijay Kanawade
  • Innocent Kudzotsa
  • Jiming Sun
  • Aaron Bansemer
  • Andrew G. Detwiler
  • Alexander Khain
  • Sarah A. Tessendorf
Visa allt

Summary, in English

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%.

Avdelning/ar

  • Institutionen för naturgeografi och ekosystemvetenskap
  • MERGE: ModElling the Regional and Global Earth system

Publiceringsår

2017-09-01

Språk

Engelska

Sidor

2789-2811

Publikation/Tidskrift/Serie

Journals of the Atmospheric Sciences

Volym

74

Issue

9

Dokumenttyp

Artikel i tidskrift

Förlag

Amer Meteorological Soc

Ämne

  • Meteorology and Atmospheric Sciences

Nyckelord

  • Cloud microphysics
  • Clouds
  • Hail
  • Ice particles

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 0022-4928