DOI: 10.1007/s00382-014-2269-3
Scopus记录号: 2-s2.0-84929707731
论文题名: Why ensemble mean projection of south Asian monsoon rainfall by CMIP5 models is not reliable?
作者: Sabeerali C.T. ; Rao S.A. ; Dhakate A.R. ; Salunke K. ; Goswami B.N.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2015
卷: 45, 期: 2017-01-02 起始页码: 161
结束页码: 174
语种: 英语
英文关键词: Climate projections
; CMIP5
; Global warming
; Indian summer monsoon rainfall
英文摘要: Future projections of the Indian summer monsoon rainfall (ISMR) and its large-scale thermodynamic driver are studied by using CMIP5 model outputs. While all models project an increasing precipitation in the future warming scenario, most of them project a weakening large-scale thermodynamic driver arising from a weakening of the upper tropospheric temperature (UTT) gradient over south Asian summer monsoon region. The weakening of the UTT gradient under global warming scenarios is related to the increase in sea surface temperature (SST) over the equatorial Indian Ocean (EIO) leading to a stronger increase of UTT over the EIO region relative to the northern Indian region, a hypothesis supported by a series of Atmospheric General Circulation Model (AGCM) experiments forced by projected SSTs. To diagnose the inconsistency between the model projections of precipitation and the large-scale thermodynamic driver, we have examined the rate of total precipitation explained by convective and stratiform precipitations in observations and in CMIP5 models. It is found that most models produce too much (little) convective (stratiform) precipitation compared to observations. In addition, we also find stronger precipitable water—precipitation relationship in most CMIP5 models as compared to observations. Hence, the atmospheric moisture content produced by the model immediately gets converted to precipitation even though the large-scale thermodynamics in models weaken. Therefore, under global warming scenarios, due to increased temperature and resultant increased atmospheric moisture supply, these models tend to produce unrealistic local convective precipitation often not in tune with other large-scale variables. Our results questions the reliability of the ISMR projections in CMIP5 models and highlight the need to improve the convective parameterization schemes in coupled models for the reliable projections of the ISMR. © 2014, Springer-Verlag Berlin Heidelberg.
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/54096
Appears in Collections: 过去全球变化的重建
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作者单位: Indian Institute of Tropical Meteorology, Pune, Maharashtra, India
Recommended Citation:
Sabeerali C.T.,Rao S.A.,Dhakate A.R.,et al. Why ensemble mean projection of south Asian monsoon rainfall by CMIP5 models is not reliable?[J]. Climate Dynamics,2015-01-01,45(2017-01-02)