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© 2014. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.

Abstract

Large-eddy simulations of mixed-phase Arctic clouds by 11 different models are analyzed with the goal of improving understanding and model representation of processes controlling the evolution of these clouds. In a case based on observations from the Indirect and Semi-Direct Aerosol Campaign (ISDAC), it is found that ice number concentration, Ni, exerts significant influence on the cloud structure. Increasing Ni leads to a substantial reduction in liquid water path (LWP), in agreement with earlier studies. In contrast to previous intercomparison studies, all models here use the same ice particle properties (i.e., mass-size, mass-fall speed, and mass-capacitance relationships) and a common radiation parameterization. The constrained setup exposes the importance of ice particle size distributions (PSDs) in influencing cloud evolution. A clear separation in LWP and IWP predicted by models with bin and bulk microphysical treatments is documented and attributed primarily to the assumed shape of ice PSD used in bulk schemes. Compared to the bin schemes that explicitly predict the PSD, schemes assuming exponential ice PSD underestimate ice growth by vapor deposition and overestimate mass-weighted fall speed leading to an underprediction of IWP by a factor of two in the considered case. Sensitivity tests indicate LWP and IWP are much closer to the bin model simulations when a modified shape factor which is similar to that predicted by bin model simulation is used in bulk scheme. These results demonstrate the importance of representation of ice PSD in determining the partitioning of liquid and ice and the longevity of mixed-phase clouds.

Details

Title
Intercomparison of large-eddy simulations of Arctic mixed-phase clouds: Importance of ice size distribution assumptions
Author
Ovchinnikov, Mikhail 1 ; Ackerman, Andrew S 2 ; Avramov, Alexander 3 ; Cheng, Anning 4 ; Fan, Jiwen 1 ; Fridlind, Ann M 2 ; Ghan, Steven 1 ; Harrington, Jerry 5 ; Hoose, Corinna 6 ; Korolev, Alexei 7 ; McFarquhar, Greg M 8 ; Morrison, Hugh 9 ; Paukert, Marco 6 ; Savre, Julien 10 ; Shipway, Ben J 11 ; Shupe, Matthew D 12 ; Solomon, Amy 12 ; Sulia, Kara 13 

 Pacific Northwest National Laboratory, Richland, Washington, USA 
 NASA Goddard Institute for Space Studies, New York, New York, USA 
 Center for Global Change Science, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA 
 Science Systems and Applications Inc./NASA LaRC, Hampton, Virginia, USA 
 Department of Meteorology, Pennsylvania State University, University Park, State College, Pennsylvania, USA 
 Karlsruhe Institute of Technology, Karlsruhe, Germany 
 Environment Canada, Toronto, Ontario, Canada 
 Department of Atmospheric Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA 
 National Center for Atmospheric Research, Boulder, Colorado, USA 
10  Department of Meteorology, Stockholm University, Stockholm, Sweden 
11  Met Office, Exeter, UK 
12  Cooperative Institute for Research in Environmental Science, University of Colorado/NOAA, Boulder, Colorado, USA 
13  Geophysical Fluid Dynamics Laboratory, Princeton University, Princeton, New Jersey, USA 
Pages
223-248
Section
Research Articles
Publication year
2014
Publication date
Mar 2014
Publisher
John Wiley & Sons, Inc.
e-ISSN
19422466
Source type
Scholarly Journal
Language of publication
English
ProQuest document ID
2299163070
Copyright
© 2014. This work is published under https://creativecommons.org/licenses/by/4.0/ (the “License”). Notwithstanding the ProQuest Terms and Conditions, you may use this content in accordance with the terms of the License.