DOI: 10.1175/JCLI-D-14-00184.1
Scopus记录号: 2-s2.0-84922782271
论文题名: Regional assessments of low clouds against large-scale stability in CAM5 and CAM-CLUBB using MODIS and ERA-Interim reanalysis data
作者: Kubar T.L. ; Stephens G.L. ; Lebsock M. ; Larson V.E. ; Bogenschutz P.A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2015
卷: 28, 期: 4 起始页码: 1685
结束页码: 1706
语种: 英语
Scopus关键词: Cams
; Clouds
; Commerce
; Radiometers
; Cloud top heights
; Community atmosphere model
; Large-scale dynamics
; Moist static energy
; North-eastern Pacific
; Overcast low cloud
; Smooth transitions
; Strong stability
; Probability density function
; atmospheric modeling
; cloud cover
; MODIS
; parameterization
; probability density function
; regional climate
; stratocumulus
英文摘要: Daily gridded cloud data from MODIS and ERA-Interim reanalysis have been assessed to examine variations of low cloud fraction (CF) and cloud-top height and their dependence on large-scale dynamics and a measure of stability. To assess the stratocumulus (Sc) to cumulus (Cu) transition (STCT), the observations are used to evaluate two versions of the NCAR Community Atmosphere Model version 5 (CAM5), both the base model and a version that has implemented a new subgrid low cloud parameterization, Cloud Layers Unified by Binormals (CLUBB). The ratio of moist static energy (MSE) at 700-1000 hPa (MSEtotal) is a skillful predictor of median CF of screened low cloud grids. Values of MSEtotal less than 1.00 represent either conditionally or absolutely unstable layers, and probability density functions of CF suggest a preponderance of either trade Cu (median CF<0.4) or transitional Sc clouds (0.41.00), an abundance of overcast or nearly overcast low clouds exists. While both MODIS and ERA-Interim indicate a fairly smooth transition between the low cloud regimes, CAM5-Base simulates an abrupt shift from trade Cu to Sc, with trade Cu covering both too much area and occurring over excessively strong stabilities. In contrast, CAM-CLUBB simulates a smoother trade Cu to Sc transition (CTST) as a function of MSEtotal, albeit with too extensive coverage of overcast Sc in the primary northeastern Pacific subsidence region. While the overall CF distribution in CAM-CLUBB is more realistic, too few transitional clouds are simulated for intermediate MSEtotal compared to observations. © 2015 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/50460
Appears in Collections: 气候变化事实与影响
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作者单位: Department of Atmospheric Science, Colorado State University, Fort Collins, CO, United States; Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, United States; University of Wisconsin-Milwaukee, Milwaukee, WI, United States; National Center for Atmospheric Research, Boulder, CO, United States
Recommended Citation:
Kubar T.L.,Stephens G.L.,Lebsock M.,et al. Regional assessments of low clouds against large-scale stability in CAM5 and CAM-CLUBB using MODIS and ERA-Interim reanalysis data[J]. Journal of Climate,2015-01-01,28(4)