Ice aspect ratio influences on mixed-phase clouds: Impacts on phase partitioning in parcel models

Kara J. Sulia, Jerry Y. Harrington

Research output: Contribution to journalArticle

46 Citations (Scopus)

Abstract

The influences of evolving ice habit on the maintenance and glaciation of stratiform mixed-phase clouds are examined theoretically. Unlike most current modeling methods where a single axis length is predicted, the primary habits, or two axis lengths, are computed explicitly. The method produces a positive non-linear feedback between mass growth and crystal aspect ratio evolution. Furthermore, ice particle growth has a distinct initial-size dependence with smaller initial ice particles evolving into more extreme crystal shapes with greater overall mass. This feedback cannot be captured with simpler growth methods, leading to underestimates of ice growth and mixed-phase glaciation. Aspect ratio prediction is most critical for mixed-phase maintenance at temperatures where pronounced habits exist (dendritic growth, T = -15C and needle growth, -6C) and at ice concentrations between 1 L-1 and 100 L-1. At these temperatures and concentrations, rates of glaciation can be under-predicted by as much as an order of magnitude by equivalent density spheres. Habit prediction is less important for the maintenance of liquid at lower ice concentrations (<0.1 L-1) as the time-scale for liquid depletion is relatively long (days). At higher concentrations (>100 L -1) the time-scale for liquid depletion is shorter (minutes), thus predicting crystal habit has only a small impact on liquid lifetime. Updraft strength also affects mixed-phase cloud maintenance primarily at ice concentrations between 1 L-1 and 100 L-1. It is theoretically possible for vertical oscillating motions to maintain stratiform mixed-phase clouds indefinitely when temperatures are relatively high (> -10C) and ice concentrations are relatively low (<0.1 L-1).

Original languageEnglish (US)
Article numberD21309
JournalJournal of Geophysical Research Atmospheres
Volume116
Issue number21
DOIs
StatePublished - Jan 1 2011

Fingerprint

Ice
aspect ratio
Aspect ratio
ice
partitioning
habits
maintenance
glaciation
crystals
crystal
liquid
liquids
Liquids
vertical air currents
Feedback
temperature
Crystals
prediction
updraft
Crystallization

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

Cite this

@article{bcedb620c6c846c6a717bfd8460c232d,
title = "Ice aspect ratio influences on mixed-phase clouds: Impacts on phase partitioning in parcel models",
abstract = "The influences of evolving ice habit on the maintenance and glaciation of stratiform mixed-phase clouds are examined theoretically. Unlike most current modeling methods where a single axis length is predicted, the primary habits, or two axis lengths, are computed explicitly. The method produces a positive non-linear feedback between mass growth and crystal aspect ratio evolution. Furthermore, ice particle growth has a distinct initial-size dependence with smaller initial ice particles evolving into more extreme crystal shapes with greater overall mass. This feedback cannot be captured with simpler growth methods, leading to underestimates of ice growth and mixed-phase glaciation. Aspect ratio prediction is most critical for mixed-phase maintenance at temperatures where pronounced habits exist (dendritic growth, T = -15C and needle growth, -6C) and at ice concentrations between 1 L-1 and 100 L-1. At these temperatures and concentrations, rates of glaciation can be under-predicted by as much as an order of magnitude by equivalent density spheres. Habit prediction is less important for the maintenance of liquid at lower ice concentrations (<0.1 L-1) as the time-scale for liquid depletion is relatively long (days). At higher concentrations (>100 L -1) the time-scale for liquid depletion is shorter (minutes), thus predicting crystal habit has only a small impact on liquid lifetime. Updraft strength also affects mixed-phase cloud maintenance primarily at ice concentrations between 1 L-1 and 100 L-1. It is theoretically possible for vertical oscillating motions to maintain stratiform mixed-phase clouds indefinitely when temperatures are relatively high (> -10C) and ice concentrations are relatively low (<0.1 L-1).",
author = "Sulia, {Kara J.} and Harrington, {Jerry Y.}",
year = "2011",
month = "1",
day = "1",
doi = "10.1029/2011JD016298",
language = "English (US)",
volume = "116",
journal = "Journal of Geophysical Research: Atmospheres",
issn = "2169-897X",
number = "21",

}

Ice aspect ratio influences on mixed-phase clouds : Impacts on phase partitioning in parcel models. / Sulia, Kara J.; Harrington, Jerry Y.

In: Journal of Geophysical Research Atmospheres, Vol. 116, No. 21, D21309, 01.01.2011.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Ice aspect ratio influences on mixed-phase clouds

T2 - Impacts on phase partitioning in parcel models

AU - Sulia, Kara J.

AU - Harrington, Jerry Y.

PY - 2011/1/1

Y1 - 2011/1/1

N2 - The influences of evolving ice habit on the maintenance and glaciation of stratiform mixed-phase clouds are examined theoretically. Unlike most current modeling methods where a single axis length is predicted, the primary habits, or two axis lengths, are computed explicitly. The method produces a positive non-linear feedback between mass growth and crystal aspect ratio evolution. Furthermore, ice particle growth has a distinct initial-size dependence with smaller initial ice particles evolving into more extreme crystal shapes with greater overall mass. This feedback cannot be captured with simpler growth methods, leading to underestimates of ice growth and mixed-phase glaciation. Aspect ratio prediction is most critical for mixed-phase maintenance at temperatures where pronounced habits exist (dendritic growth, T = -15C and needle growth, -6C) and at ice concentrations between 1 L-1 and 100 L-1. At these temperatures and concentrations, rates of glaciation can be under-predicted by as much as an order of magnitude by equivalent density spheres. Habit prediction is less important for the maintenance of liquid at lower ice concentrations (<0.1 L-1) as the time-scale for liquid depletion is relatively long (days). At higher concentrations (>100 L -1) the time-scale for liquid depletion is shorter (minutes), thus predicting crystal habit has only a small impact on liquid lifetime. Updraft strength also affects mixed-phase cloud maintenance primarily at ice concentrations between 1 L-1 and 100 L-1. It is theoretically possible for vertical oscillating motions to maintain stratiform mixed-phase clouds indefinitely when temperatures are relatively high (> -10C) and ice concentrations are relatively low (<0.1 L-1).

AB - The influences of evolving ice habit on the maintenance and glaciation of stratiform mixed-phase clouds are examined theoretically. Unlike most current modeling methods where a single axis length is predicted, the primary habits, or two axis lengths, are computed explicitly. The method produces a positive non-linear feedback between mass growth and crystal aspect ratio evolution. Furthermore, ice particle growth has a distinct initial-size dependence with smaller initial ice particles evolving into more extreme crystal shapes with greater overall mass. This feedback cannot be captured with simpler growth methods, leading to underestimates of ice growth and mixed-phase glaciation. Aspect ratio prediction is most critical for mixed-phase maintenance at temperatures where pronounced habits exist (dendritic growth, T = -15C and needle growth, -6C) and at ice concentrations between 1 L-1 and 100 L-1. At these temperatures and concentrations, rates of glaciation can be under-predicted by as much as an order of magnitude by equivalent density spheres. Habit prediction is less important for the maintenance of liquid at lower ice concentrations (<0.1 L-1) as the time-scale for liquid depletion is relatively long (days). At higher concentrations (>100 L -1) the time-scale for liquid depletion is shorter (minutes), thus predicting crystal habit has only a small impact on liquid lifetime. Updraft strength also affects mixed-phase cloud maintenance primarily at ice concentrations between 1 L-1 and 100 L-1. It is theoretically possible for vertical oscillating motions to maintain stratiform mixed-phase clouds indefinitely when temperatures are relatively high (> -10C) and ice concentrations are relatively low (<0.1 L-1).

UR - http://www.scopus.com/inward/record.url?scp=81255211669&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=81255211669&partnerID=8YFLogxK

U2 - 10.1029/2011JD016298

DO - 10.1029/2011JD016298

M3 - Article

AN - SCOPUS:81255211669

VL - 116

JO - Journal of Geophysical Research: Atmospheres

JF - Journal of Geophysical Research: Atmospheres

SN - 2169-897X

IS - 21

M1 - D21309

ER -