Identification

Title

The 94-GHz radar dim band: Relevance to ice cloud properties and cloudsat

Abstract

Details of the microphysics are shown to be responsible for a region of ice cloud which, when probed from above, has decreasing radar reflectivity (Ze ) downwards at 94 GHz but increasing Z e at 9.7 GHz. This 94-GHz radar dim band is found to be due to the combination of ice particle aggregation and non-Rayleigh scattering effects. Observations and model calculations indicate that it occurs when the particle size distribution (PSD) broadens such that its slope, as derived from fitted PSD, decreases below about 15 cm⁻¹, or equivalently, to a median volume diameter exceeding 0.25 cm. Dimming occurs at temperatures (T) primarily between −5 and 0°C but can occur at −30°C or below in convectively-generated ice clouds (anvils). The dimming effect may produce an appreciable low bias in the ice water content (IWC) retrieved from Z measured by CloudSat's 94-GHz radar. Methods to estimate the IWC in the dim band are proposed.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d7gq6xx8

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

2008-02-01T00:00:00Z

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