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Title: An Evaluation of Marine Boundary Layer Cloud Property Simulations in the Community Atmosphere Model Using Satellite Observations: Conventional Subgrid Parameterization versus CLUBB

Abstract

This paper presents a satellite-observation-based evaluation of the marine boundary layer (MBL) cloud properties from two Community Atmosphere Model, version 5 (CAM5), simulations, one with the standard parameterization schemes (CAM5–Base) and the other with the Cloud Layers Unified by Binormals scheme (CAM5–CLUBB). Herein, when comparing the direct model outputs, the authors find that CAM5–CLUBB produces more MBL clouds, a smoother transition from stratocumulus to cumulus, and a tighter correlation between in-cloud water and cloud fraction than CAM5–Base. In the model-to-observation comparison using the COSP satellite simulators, the authors find that both simulations capture the main features and spatial patterns of the observed cloud fraction from MODIS and shortwave cloud radiative forcing (SWCF) from CERES. However, CAM5–CLUBB suffers more than CAM5–Base from a problem that can be best summarized as “undetectable” clouds (i.e., a significant fraction of simulated MBL clouds are thinner than the MODIS detection threshold). This issue leads to a smaller COSP–MODIS cloud fraction and a weaker SWCF in CAM5–CLUBB than the observations and also CAM5–Base in the tropical descending regions. Finally, the authors compare modeled radar reflectivity with CloudSat observations and find that both simulations, especially CAM5–CLUBB, suffer from an excessive drizzle problem. Further analysis reveals that themore » subgrid precipitation enhancement factors in CAM5–CLUBB are unrealistically large, which makes MBL clouds precipitate too excessively, and in turn results in too many undetectable thin clouds.« less

Authors:
 [1];  [2];  [3];  [3];  [4]
  1. Joint Center for Earth Systems Technology, University of Maryland, Baltimore County, Baltimore, Maryland
  2. Joint Center for Earth Systems Technology, and Physics Department, University of Maryland, Baltimore County, Baltimore, Maryland
  3. Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington
  4. Institute for Climate and Global Change Research, and School of Atmospheric Sciences, Nanjing University, Nanjing, China
Publication Date:
Research Org.:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Biological and Environmental Research (BER) (SC-23); Minister of Science and Technology of China; National Science Foundation (NSF); National Aeronautic and Space Administration (NASA)
OSTI Identifier:
1421778
Alternate Identifier(s):
OSTI ID: 1430421
Report Number(s):
PNNL-SA-125816
Journal ID: ISSN 0894-8755
Grant/Contract Number:  
SC0014641; 2017YFA0604001; AC05-76RL01830; CNS-0821258; CNS-1228778; DMS-0821311
Resource Type:
Published Article
Journal Name:
Journal of Climate
Additional Journal Information:
Journal Name: Journal of Climate Journal Volume: 31 Journal Issue: 6; Journal ID: ISSN 0894-8755
Publisher:
American Meteorological Society
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Satellite observations; Climate models; Cloud parameterizations; Model comparison; Model evaluation/performance; Subgrid-scale processes

Citation Formats

Song, Hua, Zhang, Zhibo, Ma, Po-Lun, Ghan, Steven J., and Wang, Minghuai. An Evaluation of Marine Boundary Layer Cloud Property Simulations in the Community Atmosphere Model Using Satellite Observations: Conventional Subgrid Parameterization versus CLUBB. United States: N. p., 2018. Web. doi:10.1175/JCLI-D-17-0277.1.
Song, Hua, Zhang, Zhibo, Ma, Po-Lun, Ghan, Steven J., & Wang, Minghuai. An Evaluation of Marine Boundary Layer Cloud Property Simulations in the Community Atmosphere Model Using Satellite Observations: Conventional Subgrid Parameterization versus CLUBB. United States. doi:10.1175/JCLI-D-17-0277.1.
Song, Hua, Zhang, Zhibo, Ma, Po-Lun, Ghan, Steven J., and Wang, Minghuai. Mon . "An Evaluation of Marine Boundary Layer Cloud Property Simulations in the Community Atmosphere Model Using Satellite Observations: Conventional Subgrid Parameterization versus CLUBB". United States. doi:10.1175/JCLI-D-17-0277.1.
@article{osti_1421778,
title = {An Evaluation of Marine Boundary Layer Cloud Property Simulations in the Community Atmosphere Model Using Satellite Observations: Conventional Subgrid Parameterization versus CLUBB},
author = {Song, Hua and Zhang, Zhibo and Ma, Po-Lun and Ghan, Steven J. and Wang, Minghuai},
abstractNote = {This paper presents a satellite-observation-based evaluation of the marine boundary layer (MBL) cloud properties from two Community Atmosphere Model, version 5 (CAM5), simulations, one with the standard parameterization schemes (CAM5–Base) and the other with the Cloud Layers Unified by Binormals scheme (CAM5–CLUBB). Herein, when comparing the direct model outputs, the authors find that CAM5–CLUBB produces more MBL clouds, a smoother transition from stratocumulus to cumulus, and a tighter correlation between in-cloud water and cloud fraction than CAM5–Base. In the model-to-observation comparison using the COSP satellite simulators, the authors find that both simulations capture the main features and spatial patterns of the observed cloud fraction from MODIS and shortwave cloud radiative forcing (SWCF) from CERES. However, CAM5–CLUBB suffers more than CAM5–Base from a problem that can be best summarized as “undetectable” clouds (i.e., a significant fraction of simulated MBL clouds are thinner than the MODIS detection threshold). This issue leads to a smaller COSP–MODIS cloud fraction and a weaker SWCF in CAM5–CLUBB than the observations and also CAM5–Base in the tropical descending regions. Finally, the authors compare modeled radar reflectivity with CloudSat observations and find that both simulations, especially CAM5–CLUBB, suffer from an excessive drizzle problem. Further analysis reveals that the subgrid precipitation enhancement factors in CAM5–CLUBB are unrealistically large, which makes MBL clouds precipitate too excessively, and in turn results in too many undetectable thin clouds.},
doi = {10.1175/JCLI-D-17-0277.1},
journal = {Journal of Climate},
number = 6,
volume = 31,
place = {United States},
year = {2018},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1175/JCLI-D-17-0277.1

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Cited by: 4 works
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