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An empirical parameterization of heterogeneous ice nucleation for multiple chemical species of aerosol

Phillips, Vaughan LU ; DeMott, Paul J. and Andronache, Constantin (2008) In Journal of Atmospheric Sciences 65(9). p.2757-2783
Abstract
A novel, flexible framework is proposed for parameterizing the heterogeneous nucleation of ice within clouds. It has empirically derived dependencies on the chemistry and surface area of multiple species of ice nucleus (IN) aerosols. Effects from variability in mean size, spectral width, and mass loading of aerosols are represented via their influences on surface area. The parameterization is intended for application in largescale atmospheric and cloud models that can predict 1) the supersaturation of water vapor, which requires a representation of vertical velocity on the cloud scale, and 2) concentrations of a variety of insoluble aerosol species. Observational data constraining the parameterization are principally from coincident field... (More)
A novel, flexible framework is proposed for parameterizing the heterogeneous nucleation of ice within clouds. It has empirically derived dependencies on the chemistry and surface area of multiple species of ice nucleus (IN) aerosols. Effects from variability in mean size, spectral width, and mass loading of aerosols are represented via their influences on surface area. The parameterization is intended for application in largescale atmospheric and cloud models that can predict 1) the supersaturation of water vapor, which requires a representation of vertical velocity on the cloud scale, and 2) concentrations of a variety of insoluble aerosol species. Observational data constraining the parameterization are principally from coincident field studies of IN activity and insoluble aerosol in the troposphere. The continuous flow diffusion chamber (CFDC) was deployed. Aerosol species are grouped by the parameterization into three basic types: dust and metallic compounds, inorganic black carbon, and insoluble organic aerosols. Further field observations inform the partitioning of measured IN concentrations among these basic groups of aerosol. The scarcity of heterogeneous nucleation, observed at humidities well below water saturation for warm subzero temperatures, is represented. Conventional and inside- out contact nucleation by IN is treated with a constant shift of their freezing temperatures. The empirical parameterization is described and compared with available field and laboratory observations and other schemes. Alternative schemes differ by up to five orders of magnitude in their freezing fractions (-30 degrees C). New knowledge from future observational advances may be easily assimilated into the scheme's framework. The essence of this versatile framework is the use of data concerning atmospheric IN sampled directly from the troposphere. (Less)
Please use this url to cite or link to this publication:
author
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Atmospheric Sciences
volume
65
issue
9
pages
2757 - 2783
publisher
Amer Meteorological Soc
external identifiers
  • wos:000259378800001
  • scopus:40449130337
ISSN
1520-0469
DOI
10.1175/2007JAS2546.1
language
English
LU publication?
no
id
8dfa0f3f-284e-432d-8b55-bc3e5c6110f4 (old id 4587499)
date added to LUP
2014-08-15 10:23:31
date last changed
2017-09-24 03:36:37
@article{8dfa0f3f-284e-432d-8b55-bc3e5c6110f4,
  abstract     = {A novel, flexible framework is proposed for parameterizing the heterogeneous nucleation of ice within clouds. It has empirically derived dependencies on the chemistry and surface area of multiple species of ice nucleus (IN) aerosols. Effects from variability in mean size, spectral width, and mass loading of aerosols are represented via their influences on surface area. The parameterization is intended for application in largescale atmospheric and cloud models that can predict 1) the supersaturation of water vapor, which requires a representation of vertical velocity on the cloud scale, and 2) concentrations of a variety of insoluble aerosol species. Observational data constraining the parameterization are principally from coincident field studies of IN activity and insoluble aerosol in the troposphere. The continuous flow diffusion chamber (CFDC) was deployed. Aerosol species are grouped by the parameterization into three basic types: dust and metallic compounds, inorganic black carbon, and insoluble organic aerosols. Further field observations inform the partitioning of measured IN concentrations among these basic groups of aerosol. The scarcity of heterogeneous nucleation, observed at humidities well below water saturation for warm subzero temperatures, is represented. Conventional and inside- out contact nucleation by IN is treated with a constant shift of their freezing temperatures. The empirical parameterization is described and compared with available field and laboratory observations and other schemes. Alternative schemes differ by up to five orders of magnitude in their freezing fractions (-30 degrees C). New knowledge from future observational advances may be easily assimilated into the scheme's framework. The essence of this versatile framework is the use of data concerning atmospheric IN sampled directly from the troposphere.},
  author       = {Phillips, Vaughan and DeMott, Paul J. and Andronache, Constantin},
  issn         = {1520-0469},
  language     = {eng},
  number       = {9},
  pages        = {2757--2783},
  publisher    = {Amer Meteorological Soc},
  series       = {Journal of Atmospheric Sciences},
  title        = {An empirical parameterization of heterogeneous ice nucleation for multiple chemical species of aerosol},
  url          = {http://dx.doi.org/10.1175/2007JAS2546.1},
  volume       = {65},
  year         = {2008},
}