Title: Differences in Ice Cloud Optical Depth From CALIPSO and Ground-Based Raman Lidar at the ARM SGP and TWP Sites

Abstract

Ice cloud column optical depths from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite and ground-based Raman lidars (RLs) at the Atmospheric Radiation Measurement (ARM) Southern Great Plains (SGP) and Tropical Western Pacific (TWP) sites are compared for 8 and 4 years, respectively. The cloudy mean ice cloud column optical depths from CALIPSO Version 4 data product with a horizontal resolution of 5 km are 78% (63%) larger than those from the RLs with a resolution of 10 min/30 m at SGP (TWP) for collocated transparent profiles. The main difference at SGP is caused by the lidar ratio that for CALIPSO is related to its treatment of the multiple scattering factor. The main difference at TWP is caused by the averaging resolution. Large differences in the optical depth distribution between the CALIPSO and RL are found for small optical depths at both sites, which are due to optically very thin clouds only detectable by the RLs. The differences in ice cloud column optical depth distributions and their mean values between the CALIPSO and RL can largely be reconciled over both sites after accounting for the averaging resolutions, lidar ratios along with the CALIPSO multiple scattering factor treatment, sensitivitymore » to optically very thin ice clouds, and definition of transparent profiles. This work also examines in detail the lidar ratios that are directly observed by the RLs, which does not support the temperature-dependent parameterizations of ice cloud lidar ratio and multiple scattering factor used in CALIPSO's Version 4 data product.« less

Authors:

Balmes, K. A.  ^[1];

• Search DOE PAGES for author "Balmes, K. A."
• Search DOE PAGES for ORCID "0000-0003-0898-5177"

Fu, Q.  ^[1];

• Search DOE PAGES for author "Fu, Q."
• Search DOE PAGES for ORCID "0000-0001-5371-8460"

Thorsen, T. J.  ^[2]

• Search DOE PAGES for author "Thorsen, T. J."
• Search DOE PAGES for ORCID "0000-0002-4405-3572"

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+ Show Author Affiliations

1. Univ. of Washington, Seattle, WA (United States)
2. NASA Langley Research Center, Hampton, VA (United States)

Publication Date:

Wed Jan 16 00:00:00 EST 2019

Research Org.:

Univ. of Washington, Seattle, WA (United States)

Sponsoring Org.:

USDOE Office of Science (SC), Biological and Environmental Research (BER); National Aeronautics and Space Administration (NASA)

OSTI Identifier:

1612864

Alternate Identifier(s):

OSTI ID: 1494392

Grant/Contract Number:  

SC0018190; NNX16AO95G

Resource Type:

Accepted Manuscript

Journal Name:

Journal of Geophysical Research: Atmospheres

Additional Journal Information:

Journal Volume: 124; Journal Issue: 3; Journal ID: ISSN 2169-897X

Publisher:

American Geophysical Union

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; 37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY