DOI: 10.1007/s00382-016-3151-2
Scopus记录号: 2-s2.0-84976320895
论文题名: An assessment of Indian monsoon seasonal forecasts and mechanisms underlying monsoon interannual variability in the Met Office GloSea5-GC2 system
作者: Johnson S.J. ; Turner A. ; Woolnough S. ; Martin G. ; MacLachlan C.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 48, 期: 2017-05-06 起始页码: 1447
结束页码: 1465
语种: 英语
英文关键词: Indian monsoon
; Indian Ocean dipole
; Seasonal forecasting
英文摘要: We assess Indian summer monsoon seasonal forecasts in GloSea5-GC2, the Met Office fully coupled subseasonal to seasonal ensemble forecasting system. Using several metrics, GloSea5-GC2 shows similar skill to other state-of-the-art seasonal forecast systems. The prediction skill of the large-scale South Asian monsoon circulation is higher than that of Indian monsoon rainfall. Using multiple linear regression analysis we evaluate relationships between Indian monsoon rainfall and five possible drivers of monsoon interannual variability. Over the time period studied (1992–2011), the El Niño-Southern Oscillation (ENSO) and the Indian Ocean dipole (IOD) are the most important of these drivers in both observations and GloSea5-GC2. Our analysis indicates that ENSO and its teleconnection with Indian rainfall are well represented in GloSea5-GC2. However, the relationship between the IOD and Indian rainfall anomalies is too weak in GloSea5-GC2, which may be limiting the prediction skill of the local monsoon circulation and Indian rainfall. We show that this weak relationship likely results from a coupled mean state bias that limits the impact of anomalous wind forcing on SST variability, resulting in erroneous IOD SST anomalies. Known difficulties in representing convective precipitation over India may also play a role. Since Indian rainfall responds weakly to the IOD, it responds more consistently to ENSO than in observations. Our assessment identifies specific coupled biases that are likely limiting GloSea5-GC2 Indian summer monsoon seasonal prediction skill, providing targets for model improvement. © 2016, Springer-Verlag Berlin Heidelberg. 资助项目: MoES, Ministry of Earth Sciences
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53313
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Meteorology, National Centre for Atmospheric Science, University of Reading, Earley Gate, Reading, United Kingdom; ECMWF, Shinfield Park, Reading, United Kingdom; Met Office Hadley Centre, FitzRoy Road, Exeter, United Kingdom
Recommended Citation:
Johnson S.J.,Turner A.,Woolnough S.,et al. An assessment of Indian monsoon seasonal forecasts and mechanisms underlying monsoon interannual variability in the Met Office GloSea5-GC2 system[J]. Climate Dynamics,2017-01-01,48(2017-05-06)