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Title: A multiscale modeling framework model (superparameterized CAM5) with a higher-order turbulence closure: Model description and low-cloud simulations

In this study, a higher-order turbulence closure scheme, called Cloud Layers Unified by Binormals (CLUBB), is implemented into a Multi-scale Modeling Framework (MMF) model to improve low cloud simulations. The performance of CLUBB in MMF simulations with two different microphysics configurations (one-moment cloud microphysics without aerosol treatment and two-moment cloud microphysics coupled with aerosol treatment) is evaluated against observations and further compared with results from the Community Atmosphere Model, Version 5 (CAM5) with conventional cloud parameterizations. CLUBB is found to improve low cloud simulations in the MMF, and the improvement is particularly evident in the stratocumulus-to-cumulus transition regions. Compared to the single-moment cloud microphysics, CLUBB with two-moment microphysics produces clouds that are closer to the coast, and agrees better with observations. In the stratocumulus-to cumulus transition regions, CLUBB with two-moment cloud microphysics produces shortwave cloud forcing in better agreement with observations, while CLUBB with single moment cloud microphysics overestimates shortwave cloud forcing. CLUBB is further found to produce quantitatively similar improvements in the MMF and CAM5, with slightly better performance in the MMF simulations (e.g., MMF with CLUBB generally produces low clouds that are closer to the coast than CAM5 with CLUBB). As a result, improved low cloud simulations inmore » MMF make it an even more attractive tool for studying aerosol-cloud-precipitation interactions.« less
Authors:
 [1] ;  [2] ;  [3] ;  [3] ;  [2] ;  [3] ;  [4] ;  [3] ;  [5]
  1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Nanjing Univ., Nanjing (China)
  2. Univ. of Wisconsin-Milwaukee, Milwaukee, WI (United States)
  3. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
  4. Univ. of Wyoming, Laramie, WY (United States)
  5. Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Institute of Atmospheric Physics, Beijing (China); Chinese Academy of Sciences, Beijing (China)
Publication Date:
Report Number(s):
PNNL-SA-104723
Journal ID: ISSN 1942-2466; KP1703010
Grant/Contract Number:
AC05-76RL01830; AC05-00OR22725
Type:
Published Article
Journal Name:
Journal of Advances in Modeling Earth Systems
Additional Journal Information:
Journal Volume: 7; Journal Issue: 2; Journal ID: ISSN 1942-2466
Publisher:
American Geophysical Union (AGU)
Research Org:
Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
Sponsoring Org:
USDOE
Country of Publication:
United States
Language:
English
Subject:
54 ENVIRONMENTAL SCIENCES; cloud layers unified by binormals; CLUBB; higher-order turbulence; low cloud simulations
OSTI Identifier:
1295973
Alternate Identifier(s):
OSTI ID: 1208771; OSTI ID: 1295974