Refinements to ice particle mass dimensional and terminal velocity relationships for ice clouds. Part II: Evaluation and parameterizations of ensemble ice particle sedimentation velocities

This two-part study addresses the development of reliable estimates of the mass and fall speed of single ice particles and ensembles. Part I of the study reports temperature-dependent coefficients for the mass-dimensional relationship, m = aDb, where D is particle maximum dimension. The fall velocit...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the atmospheric sciences 2007-04, Vol.64 (4), p.1068-1088
Main Authors: HEYMSFIELD, Andrew J, VAN ZADELHOFF, Gerd-Jan, DONOVAN, David P, FABRY, Frederic, HOGAN, Robin J, ILLINGWORTH, Anthony J
Format: Article
Language:English
Subjects:
Atoms & subatomic particles
Climate models
Clouds
Doppler radar
Earth, ocean, space
Estimates
Exact sciences and technology
External geophysics
General circulation models
Ice
Meteorology
Methods
Physics of the high neutral atmosphere
Radar
Remote sensing
Temperature
Water content
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This two-part study addresses the development of reliable estimates of the mass and fall speed of single ice particles and ensembles. Part I of the study reports temperature-dependent coefficients for the mass-dimensional relationship, m = aDb, where D is particle maximum dimension. The fall velocity relationship, Vt = ADB, is developed from observations in synoptic and low-latitude, convectively generated, ice cloud layers, sampled over a wide range of temperatures using an assumed range for the exponent b. Values for a, A, and B were found that were consistent with the measured particle size distributions (PSD) and the ice water content (IWC). To refine the estimates of coefficients a and b to fit both lower and higher moments of the PSD and the associated values for A and B, Part II uses the PSD from Part I plus coincident, vertically pointing Doppler radar returns. The observations and derived coefficients are used to evaluate earlier, single-moment, bulk ice microphysical parameterization schemes as well as to develop improved, statistically based, microphysical relationships. They may be used in cloud and climate models, and to retrieve cloud properties from ground-based Doppler radar and spaceborne, conventional radar returns.
ISSN:0022-4928
1520-0469
DOI:10.1175/JAS3900.1