Identification

Title

Comparison study of heterogeneous ice nucleation parameterizations in a parcel model framework

Abstract

A liquid-phase Lagrangian parcel model was expanded to include nucleation and growth of ice crystals. Intercomparisons between three heterogeneous ice nucleation parameterizations that link aerosol type and number to ice crystal concentration were conducted. Results indicate large differences in the prediction of ice formation in modestly supercooled clouds and in the susceptibility of cirrus to heterogeneous ice nucleation for the same assumed aerosol distribution. Only one parameterization has an observational constraint that limits the maximum ice crystal number concentrations to be a fraction of the total number concentrations of potential ice-nucleating particles (typically, all insoluble particles larger than about 0.1 μm). The constrained parameterization compares well with most ice nucleation measurements. The nonconstrained parameterizations are capable of predicting several orders of magnitude higher ice crystal concentrations than the constrained parameterization for the same parcel-forcing conditions. Ice crystal concentrations in the unconstrained parameterizations are controlled by the total number concentration of potential ice-nucleating particles and, importantly, negative feedback on ice supersaturation. This feedback control often masks the large discrepancy that exists between predicted ice crystal number concentrations and the maximum number concentrations that can be attributed to atmospheric ice nuclei based on our current understanding of the latter. It also permits unrealistic conclusions regarding the role of certain aerosols as ice nuclei. It is recommended that a constraint on ice crystal number concentrations, related to number concentrations of relevant aerosol particles, should be included in ice nucleation parameterizations used in cloud to global-scale models.

Resource type

document

Resource locator

Unique resource identifier

code

http://n2t.net/ark:/85065/d71n824n

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

Classification of spatial data and services

Topic category

geoscientificInformation

Keywords

Keyword set

keyword value

Text

originating controlled vocabulary

title

Resource Type

reference date

date type

publication

effective date

2016-01-01T00:00:00Z

Geographic location

West bounding longitude

East bounding longitude

North bounding latitude

South bounding latitude

Temporal reference

Temporal extent

Begin position

End position

Dataset reference date

date type

publication

effective date

2009-03-17T00:00:00Z

Frequency of update

Quality and validity

Lineage

Conformity

Data format

name of format

version of format

Constraints related to access and use

Constraint set

Use constraints

Limitations on public access

None

Responsible organisations

Responsible party

contact position

OpenSky Support

organisation name

UCAR/NCAR - Library

full postal address

PO Box 3000

Boulder

80307-3000

email address

opensky@ucar.edu

web address

http://opensky.ucar.edu/

name: homepage

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact