DOI: 10.1175/JCLI-D-11-00521.1
Scopus记录号: 2-s2.0-84867671533
论文题名: Sensitivity of cloud liquid water content estimates to the temperature-dependent thermodynamic phase: A global study using cloudsat data
作者: Devasthale A. ; Thomas M.A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2012
卷: 25, 期: 20 起始页码: 7297
结束页码: 7307
语种: 英语
Scopus关键词: Cloud liquid waters
; CloudSat
; Data sets
; High Latitudes
; High-latitude regions
; Ice fraction
; Low-level clouds
; Midlatitudes
; Parameterizations
; Quantitative estimates
; Radiative impacts
; Reanalysis
; Seasonal mean
; Sensitivity studies
; Sub-zero temperatures
; Subfreezing temperatures
; Temperature dependent
; Temperature range
; Vertical profile
; Climate models
; Clouds
; Estimation
; Remote sensing
; Thermodynamics
; Tropics
; Liquids
; climate modeling
; cloud cover
; cloud microphysics
; CloudSat
; condensate
; convective cloud
; estimation method
; parameterization
; quantitative analysis
; satellite data
; sensitivity analysis
; temperature profile
; thermodynamics
; vertical profile
; water content
; Southern Ocean
英文摘要: The main purpose of this study is to underline the sensitivity of cloud liquid water content (LWC) estimates purely to 1) the shape of computationally simplified temperature-dependent thermodynamic phase and 2) the range of subzero temperatures covered to partition total cloud condensate into liquid and ice fractions. Linear, quadratic, or sigmoid-shaped functions for subfreezing temperatures (down to 2208 or 2408C) are often used in climate models and reanalysis datasets for partitioning total condensate. The global vertical profiles of clouds obtained from CloudSat for the 4-yr period June 2006-May 2010 are used for sensitivity analysis and the quantitative estimates of sensitivities based on these realistic cloud profiles are provided. It is found that three cloud regimes in particular-convective clouds in the tropics, low-level clouds in the northern high latitudes, and middle-level clouds over the midlatitudes and Southern Ocean-are most sensitive to assumptions on thermodynamic phase. In these clouds, the LWC estimates based purely on quadratic or sigmoid-shaped functions with a temperature range down to 2208C can differ by up to 20%-40% over the tropics (in seasonal means), 10%-30%over the midlatitudes, and up to 50% over high latitudes compared to a linear assumption. When the temperature range is extended down to 2408C, LWC estimates in the sigmoid case can be much higher than the above values over high-latitude regions compared to the commonly used case with quadratic dependency down to 2208C. This sensitivity study emphasizes the need to critically investigate radiative impacts of cloud thermodynamic phase assumptions in simplified climate models and reanalysis datasets. © 2012 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/52177
Appears in Collections: 气候变化事实与影响
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作者单位: Swedish Meteorological and Hydrological Institute, Norrköping, Sweden
Recommended Citation:
Devasthale A.,Thomas M.A.. Sensitivity of cloud liquid water content estimates to the temperature-dependent thermodynamic phase: A global study using cloudsat data[J]. Journal of Climate,2012-01-01,25(20)