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Title: A General Method for Estimating Bulk 2D Projections of Ice Particle Shape: Theory and Applications

Journal Article · · Journal of the Atmospheric Sciences
 [1];  [1]
  1. The Pennsylvania State University, University Park, Pennsylvania
+ Show Author Affiliations

The orientation of falling ice particles directly influences estimates of microphysical and radiative bulk quantities as well as in situ retrievals of size, shape, and mass. However, retrieval efforts and bulk calculations often incorporate very basic orientations or ignore these effects altogether. To address this deficiency, this study develops a general method for projecting bulk distributions of particle shape for arbitrary orientations. The Amoroso distribution provides the most general bulk aspect ratio distribution for gamma-distributed particle axis lengths. The parameters that govern the behavior of this aspect ratio distribution depend on the assumed relationship between mass, maximum dimension, and aspect ratio. Individual spheroidal geometry allows for eccentricity quantities to linearly map onto ellipse analogs, whereas aspect ratio quantities map nonlinearly. For particles viewed from their side, this analytic distinction leads to substantially larger errors in projected aspect ratio than for projected eccentricity. Distribution transformations using these mapping equations and numerical integration of projection kernels show that both truncation of size distributions and changes in Gaussian dispersion can alter the modality and shape of projection distributions. As a result, the projection process can more than triple the relative entropy between the spheroidal and projection distributions for commonly assumed model and orientation parameters. This shape uncertainty is maximized for distributions of highly eccentric particles and for particles like aggregates that are thought to fall with large canting-angle deviations. As a result, the methods used to report projected aspect ratios and the corresponding values should be questioned.

Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23)
Grant/Contract Number:
SC0012827; SC0013953
OSTI ID:
1489713
Alternate ID(s):
OSTI ID: 1611950
Journal Information:
Journal of the Atmospheric Sciences, Journal Name: Journal of the Atmospheric Sciences Journal Issue: 1 Vol. 76; ISSN 0022-4928
Publisher:
American Meteorological SocietyCopyright Statement
Country of Publication:
United States
Language:
English

References (60)

An overview of microphysical properties of Arctic clouds observed in May and July 1998 during FIRE ACE journal July 2001
The Characterization of Ice Hydrometeor Gamma Size Distributions as Volumes in N 0 – λ – μ Phase Space: Implications for Microphysical Process Modeling journal February 2015
The Theoretical Basis for the Parameterization of Ice Crystal Habits: Growth by Vapor Deposition journal May 1994
In Situ Observations of the Microphysical Properties of Wave, Cirrus, and Anvil Clouds. Part II: Cirrus Clouds journal December 2006
Ice particle habits in stratiform clouds journal October 2000
A Multimoment Bulk Microphysics Parameterization. Part I: Analysis of the Role of the Spectral Shape Parameter journal September 2005
A New Double-Moment Microphysics Parameterization for Application in Cloud and Climate Models. Part I: Description journal June 2005
Improved Measurements of the Ice Water Content in Cirrus Using a Total-Water Probe journal April 1995
Observations and Parameterizations of Particle Size Distributions in Deep Tropical Cirrus and Stratiform Precipitating Clouds: Results from In Situ Observations in TRMM Field Campaigns journal December 2002
The behaviour of freely falling cylinders and cones in a viscous fluid journal August 1965
A laboratory investigation into the aggregation efficiency of small ice crystals journal January 2012
Polarization and Brewster angle properties of light pillars journal January 1987
Parameterization of Cloud Microphysics Based on the Prediction of Bulk Ice Particle Properties. Part I: Scheme Description and Idealized Tests journal January 2015
Free-Fall Behavior of Planar Snow Crystals, Conical Graupel and Small Hail journal January 1971
New RAMS cloud microphysics parameterization part I: the single-moment scheme journal September 1995
A Model Predicting the Evolution of Ice Particle Size Spectra and Radiative Properties of Cirrus Clouds. Part II: Dependence of Absorption and Extinction on Ice Crystal Morphology journal March 1994
The Shape and Riming Properties of Ice Crystals in Natural Clouds journal January 1969
Ricerche intorno alla curva dei redditi journal December 1925
The 2D-S (Stereo) Probe: Design and Preliminary Tests of a New Airborne, High-Speed, High-Resolution Particle Imaging Probe journal November 2006
Orientation statistics and settling velocity of ellipsoids in decaying turbulence journal June 2014
Study of Planar Ice Crystal Orientations in Ice Clouds from Scanning Polarization Lidar Observations journal May 2005
The Growth of Atmospheric Ice Crystals: A Summary of Findings in Vertical Supercooled Cloud Tunnel Studies journal June 1999
Use of Mass- and Area-Dimensional Power Laws for Determining Precipitation Particle Terminal Velocities journal June 1996
Predicting Ice Shape Evolution in a Bulk Microphysics Model journal June 2017
Fall speeds and masses of solid precipitation particles journal May 1974
Triple-Moment Modal Parameterization for the Adaptive Growth Habit of Pristine Ice Crystals journal May 2016
Processing of Ice Cloud In Situ Data Collected by Bulk Water, Scattering, and Imaging Probes: Fundamentals, Uncertainties, and Efforts toward Consistency journal January 2017
Improvement in Determination of Ice Water Content from Two-Dimensional Particle Imagery. Part II: Applications to Collected Data journal September 2006
Air Flow and Particle Trajectories around Aircraft Fuselages. Part III: Extensions to Particles of Arbitrary Shape journal December 1985
A Method for Adaptive Habit Prediction in Bulk Microphysical Models. Part I: Theoretical Development journal February 2013
Orientation Model for Particles in Turbulence journal June 1995
What Can We Conclude about the Real Aspect Ratios of Ice Particle Aggregates from Two-Dimensional Images? journal March 2017
The Spectral Ice Habit Prediction System (SHIPS). Part II: Simulation of Nucleation and Depositional Growth of Polycrystals journal October 2008
Improvement in Determination of Ice Water Content from Two-Dimensional Particle Imagery. Part I: Image-to-Mass Relationships journal September 2006
Polarimetric Signatures above the Melting Layer in Winter Storms: An Observational and Modeling Study journal March 2013
A Double-Moment Multiple-Phase Four-Class Bulk Ice Scheme. Part I: Description journal January 1994
Total Surface Area Estimates for Individual Ice Particles and Particle Populations journal April 2005
Growth of ice particle mass and projected area during riming journal January 2017
A Statistical and Physical Description of Hydrometeor Distributions in Colorado Snowstorms Using a Video Disdrometer journal May 2007
Roundness and Aspect Ratio of Particles in Ice Clouds journal August 2003
Statistical Theory on the Functional Form of Cloud Particle Size Distributions journal August 2018
A Theory of Snow-Crystal Habit and Growth journal April 1954
Orientations and aspect ratios of falling snow journal June 2015
The Dimension of Ice Crystals in Natural Clouds journal September 1970
The Spectral Ice Habit Prediction System (SHIPS). Part III: Description of the Ice Particle Model and the Habit-Dependent Aggregation Model journal June 2011
Polarimetric Radar Observation Operator for a Cloud Model with Spectral Microphysics journal April 2011
Air Flow and Particle Trajectories around Aircraft Fuselages. IV: Orientation of Ice Crystals journal September 1986
Use of observed ice crystal sizes and shapes to calculate mean-scattering properties and multispectral radiances: CEPEX April 4, 1993, case study journal December 1999
Principles and applications of dual-polarization weather radar. Part I: Description of the polarimetric radar variables journal November 2013
Explicit Forecasts of Winter Precipitation Using an Improved Bulk Microphysics Scheme. Part II: Implementation of a New Snow Parameterization journal December 2008
Inferring Fall Attitudes of Pristine Dendritic Crystals from Polarimetric Radar Data journal January 2005
Single-Scattering Properties of Aggregates of Bullet Rosettes in Cirrus journal June 2007
Radar Scattering from Ice Aggregates Using the Horizontally Aligned Oblate Spheroid Approximation journal March 2012
A Method for Adaptive Habit Prediction in Bulk Microphysical Models. Part II: Parcel Model Corroboration journal February 2013
A General Equation for the Terminal Fall Speed of Solid Hydrometeors journal August 1989
A Comprehensive Habit Diagram for Atmospheric Ice Crystals: Confirmation from the Laboratory, AIRS II, and Other Field Studies journal September 2009
The Modified Gamma Size Distribution Applied to Inhomogeneous and Nonspherical Particles: Key Relationships and Conversions journal July 2011
On the Impacts of Different Definitions of Maximum Dimension for Nonspherical Particles Recorded by 2D Imaging Probes journal May 2016
The Capacitance of Pristine Ice Crystals and Aggregate Snowflakes journal January 2008
The Spectral Ice Habit Prediction System (SHIPS). Part I: Model Description and Simulation of the Vapor Deposition Process journal July 2007

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