DOI: 10.1002/joc.5480
论文题名: Mean and intra-seasonal variability simulated by NCEP Climate Forecast System model (version 2.0) during boreal winter: Impact of horizontal resolution
作者: Malviya S. ; Mukhopadhyay P. ; Phani Murali Krishna R. ; Dhakate A. ; Salunke K.
刊名: International Journal of Climatology
ISSN: 8998418
出版年: 2018
卷: 38, 期: 7 起始页码: 3028
结束页码: 3043
语种: 英语
英文关键词: boreal winter
; CFSv2
; intra-seasonal oscillations
; Madden–Julian oscillation
; MJO
; MJO diagnostics
; model resolution
; Tropics
Scopus关键词: Boundary layers
; Climatology
; Rain
; Tropics
; Boreal winters
; CFSv2
; Intra-seasonal
; Madden-Julian oscillation
; Model resolution
; Climate models
; climate oscillation
; climate prediction
; forecasting method
; intertropical convergence zone
; Madden-Julian oscillation
; rainfall
; relative humidity
; seasonal variation
; tropical environment
; winter
英文摘要: This study demonstrates the fidelity of Climate Forecast System version 2 (CFSv2) in three horizontal resolutions: T62, T126 and T382, during boreal winter. As the Madden–Julian oscillation (MJO) is the major mode of variability during boreal winter, the emphasis of the study is on the fidelity of the models in capturing the MJO variability. CFSv2 shows moderate skill in simulating the intra-seasonal oscillation and the skill is sensitive to the resolution of the model. Boreal winter mean precipitation shows the tendency of the model to overdo the double Intertropical Convergence Zone (ITCZ) that increases with resolution. Twenty to hundred days band-pass-filtered rainfall variances also indicate that the dominant variances are overestimated with increase in resolution. The characteristic eastwards propagation is not captured by the model at all the resolutions. In an attempt to understand the limitation of the model, composites of specific humidity are analysed which show that the model’s moisture profile is rather better represented at lower resolution than the higher ones. Analyses of relative humidity profile as a function of rainfall rates show that all the model resolutions fail to reproduce the lower-level moistening prior to deep convection. Observational studies have shown shallow convection to be responsible for this low-level moistening. Furthermore, analysis of mean stratiform rainfall indicates that spectrum of rainfall variability is not simulated by the model and increasing the resolution could not improve the cloud processes. This study therefore indicates that the fundamental moist convective processes do not improve in the model and neither its bias in capturing the intra-seasonal variability vis-à-vis MJO through increasing resolution. This can therefore be a basis for improving the moist convective processes with emphasis on the improvement of the shallow convection within boundary layer and also for the inclusion of scale dependencies in parameterized processes. © 2018 Royal Meteorological Society Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/116889
Appears in Collections: 气候减缓与适应
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作者单位: Indian Institute of Tropical Meteorology, Pune, India
Recommended Citation:
Malviya S.,Mukhopadhyay P.,Phani Murali Krishna R.,et al. Mean and intra-seasonal variability simulated by NCEP Climate Forecast System model (version 2.0) during boreal winter: Impact of horizontal resolution[J]. International Journal of Climatology,2018-01-01,38(7)