DOI: 10.1175/JCLI-D-12-00637.1
Scopus记录号: 2-s2.0-84881626359
论文题名: Diagnosing warm frontal cloud formation in a GCM: A novel approach using conditional subsetting
作者: Booth J.F. ; Naud C.M. ; Del Genio A.D.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2013
卷: 26, 期: 16 起始页码: 5827
结束页码: 5845
语种: 英语
Scopus关键词: Advanced microwave scanning radiometer for earth observing systems
; Cloud-aerosol lidar and infrared pathfinder satellite observations
; Extratropical cyclones
; General circulation model
; Initial structures
; Research and application
; Retrospective analysis
; Satellite observations
; Clouds
; NASA
; AMSR-E
; CALIPSO
; cloud
; CloudSat
; general circulation model
; stratiform cloud
; warm front
英文摘要: This study analyzes characteristics of clouds and vertical motion across extratropical cyclone warm fronts in the NASA Goddard Institute for Space Studies general circulation model. The validity of the modeled clouds is assessed using a combination of satellite observations from CloudSat, Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO), Advanced Microwave Scanning Radiometer for Earth Observing System (AMSR-E), and the NASA Modern-Era Retrospective Analysis for Research and Applications (MERRA) reanalysis. The analysis focuses on developing cyclones, to test the model's ability to generate their initial structure. To begin, the extratropical cyclones and their warm fronts are objectively identified and cyclone-local fields are mapped into a vertical transect centered on the surface warm front. To further isolate specific physics, the cyclones are separated using conditional subsetting based on additional cyclone-local variables, and the differences between the subset means are analyzed. Conditional subsets are created based on 1) the transect clouds and 2) vertical motion; 3) the strength of the temperature gradient along the warm front, as well as the storm-local 4) wind speed and 5) precipitable water (PW). The analysis shows that the model does not generate enough frontal cloud, especially at low altitude. The subsetting results reveal that, compared to the observations, the model exhibits a decoupling between cloud formation at high and low altitudes across warm fronts and a weak sensitivity to moisture. These issues are caused in part by the parameterized convection and assumptions in the stratiform cloud scheme that are valid in the subtropics. On the other hand, the model generates proper covariability of low-altitude vertical motion and cloud at the warm front and a joint dependence of cloudiness on wind and PW. © 2013 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/51759
Appears in Collections: 气候变化事实与影响
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作者单位: NASA Goddard Institute for Space Studies, Applied Physics and Applied Mathematics, Columbia University, New York, NY, United States; Applied Physics and Applied Mathematics, Columbia University, New York, NY, United States; NASA Goddard Institute for Space Studies, New York, NY, United States
Recommended Citation:
Booth J.F.,Naud C.M.,Del Genio A.D.. Diagnosing warm frontal cloud formation in a GCM: A novel approach using conditional subsetting[J]. Journal of Climate,2013-01-01,26(16)