Identification

Title

Estimating ice content and extinction in precipitating cloud systems from CloudSat radar measurements

Abstract

Relations between W band radar reflectivity and ice cloud water content and visible extinction coefficient are developed using a large microphysical data set. These relations are specifically tuned for CloudSat radar to derive ice content and optical thickness of ice parts of precipitating systems where other types of measurements have limitations. Accounting for nonsphericity is essential for larger particles, which produce higher reflectivities (Z e > 0 dBZ) and often dominate ice content of precipitating clouds. Typical values of median sizes in such clouds are about 1 - 2 mm, and they vary modestly. The modest particle size variability and strong non-Rayleigh scattering reduce data scatter in the derived relations and increase an exponent in best fit power law approximations for ice water content-reflectivity and extinction-reflectivity relations. The data scatter for high-reflectivity clouds is smaller than for low-reflectivity nonprecipitating clouds. It is about 33% for the reflectivity-ice water content relation, and it is about 50% for the reflectivity-extinction relation. For higher reflectivities, the temperature dependence of the ice water content-reflectivity relations is not very distinct, and uncertainties due to temperature variations are not expected to be high compared to possible errors due to particle shape variability. Uncertainties in particle aspect ratio, mass-size relation assumptions, and underrepresentation of smaller particles in samples can produce additional retrieval errors, so cloud ice content estimates can have uncertainties of about 50%, and extinction estimates can have uncertainties as large as a factor of 2.

Resource type

document

Resource locator

Unique resource identifier

code

https://n2t.org/ark:/85065/d72n52fv

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

2008-08-09T00:00:00Z

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