skip to main content
DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site

Abstract

Based on long-term observations by the Atmospheric Radiation Measurement program at its Southern Great Plains site, a new composite case of continental shallow cumulus (ShCu) convection is constructed for large-eddy simulations (LES) and single-column models. The case represents a typical daytime nonprecipitating ShCu whose formation and dissipation are driven by the local atmospheric conditions and land surface forcing and are not influenced by synoptic weather events. The case includes early morning initial profiles of temperature and moisture with a residual layer; diurnally varying sensible and latent heat fluxes, which represent a domain average over different land surface types; simplified large-scale horizontal advective tendencies and subsidence; and horizontal winds with prevailing direction and average speed. Observed composite cloud statistics are provided for model evaluation. The observed diurnal cycle is well reproduced by LES; however, the cloud amount, liquid water path, and shortwave radiative effect are generally underestimated. LES are compared between simulations with an all-or-nothing bulk microphysics and a spectral bin microphysics. The latter shows improved agreement with observations in the total cloud cover and the amount of clouds with depths greater than 300 m. When compared with radar retrievals of in-cloud air motion, LES produce comparable downdraft vertical velocities, butmore » a larger updraft area, velocity, and updraft mass flux. Both observations and LES show a significantly larger in-cloud downdraft fraction and downdraft mass flux than marine ShCu.« less

Authors:
 [1];  [1];  [2];  [3];  [4];  [1];  [1]
  1. Lawrence Livermore National Laboratory, Livermore, California
  2. Pacific Northwest National Laboratory, Richland, Washington
  3. Division of Meteorology and Physical Oceanography, University of Miami, Miami, Florida
  4. School of Marine and Atmospheric Sciences, Stony Brook University, State University of New York, Stony Brook, New York
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)
OSTI Identifier:
1392734
Alternate Identifier(s):
OSTI ID: 1398224
Report Number(s):
PNNL-SA-127650
Journal ID: ISSN 0022-4928
Grant/Contract Number:  
AC05-76RL01830
Resource Type:
Published Article
Journal Name:
Journal of the Atmospheric Sciences
Additional Journal Information:
Journal Name: Journal of the Atmospheric Sciences Journal Volume: 74 Journal Issue: 10; Journal ID: ISSN 0022-4928
Publisher:
American Meteorological Society
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; Clouds; Cumulus clouds; Large eddy simulations

Citation Formats

Zhang, Yunyan, Klein, Stephen A., Fan, Jiwen, Chandra, Arunchandra S., Kollias, Pavlos, Xie, Shaocheng, and Tang, Shuaiqi. Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site. United States: N. p., 2017. Web. doi:10.1175/JAS-D-16-0317.1.
Zhang, Yunyan, Klein, Stephen A., Fan, Jiwen, Chandra, Arunchandra S., Kollias, Pavlos, Xie, Shaocheng, & Tang, Shuaiqi. Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site. United States. doi:10.1175/JAS-D-16-0317.1.
Zhang, Yunyan, Klein, Stephen A., Fan, Jiwen, Chandra, Arunchandra S., Kollias, Pavlos, Xie, Shaocheng, and Tang, Shuaiqi. Sun . "Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site". United States. doi:10.1175/JAS-D-16-0317.1.
@article{osti_1392734,
title = {Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site},
author = {Zhang, Yunyan and Klein, Stephen A. and Fan, Jiwen and Chandra, Arunchandra S. and Kollias, Pavlos and Xie, Shaocheng and Tang, Shuaiqi},
abstractNote = {Based on long-term observations by the Atmospheric Radiation Measurement program at its Southern Great Plains site, a new composite case of continental shallow cumulus (ShCu) convection is constructed for large-eddy simulations (LES) and single-column models. The case represents a typical daytime nonprecipitating ShCu whose formation and dissipation are driven by the local atmospheric conditions and land surface forcing and are not influenced by synoptic weather events. The case includes early morning initial profiles of temperature and moisture with a residual layer; diurnally varying sensible and latent heat fluxes, which represent a domain average over different land surface types; simplified large-scale horizontal advective tendencies and subsidence; and horizontal winds with prevailing direction and average speed. Observed composite cloud statistics are provided for model evaluation. The observed diurnal cycle is well reproduced by LES; however, the cloud amount, liquid water path, and shortwave radiative effect are generally underestimated. LES are compared between simulations with an all-or-nothing bulk microphysics and a spectral bin microphysics. The latter shows improved agreement with observations in the total cloud cover and the amount of clouds with depths greater than 300 m. When compared with radar retrievals of in-cloud air motion, LES produce comparable downdraft vertical velocities, but a larger updraft area, velocity, and updraft mass flux. Both observations and LES show a significantly larger in-cloud downdraft fraction and downdraft mass flux than marine ShCu.},
doi = {10.1175/JAS-D-16-0317.1},
journal = {Journal of the Atmospheric Sciences},
number = 10,
volume = 74,
place = {United States},
year = {2017},
month = {10}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1175/JAS-D-16-0317.1

Citation Metrics:
Cited by: 8 works
Citation information provided by
Web of Science

Save / Share: