DOI: 10.1007/s00382-011-1240-9
Scopus记录号: 2-s2.0-84864391095
论文题名: The role of the intra-daily SST variability in the Indian monsoon variability and monsoon-ENSO-IOD relationships in a global coupled model
作者: Terray P. ; Kamala K. ; Masson S. ; Madec G. ; Sahai A.K. ; Luo J.-J. ; Yamagata T.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2012
卷: 39, 期: 3 起始页码: 729
结束页码: 754
语种: 英语
英文关键词: Coupled climate model
; El Niño-Southern Oscillation
; Indian summer monsoon
; Intra-daily SST variability
; Ocean-atmosphere interactions
英文摘要: The impact of diurnal SST coupling and vertical oceanic resolution on the simulation of the Indian Summer Monsoon (ISM) and its relationships with El Niño-Southern Oscillation (ENSO) and Indian Ocean Dipole (IOD) events are studied through the analysis of four integrations of a high resolution Coupled General Circulation Model (CGCM), but with different configurations. The only differences between the four integrations are the frequency of coupling between the ocean and atmosphere for the Sea Surface Temperature (SST) parameter (2 vs. 24 h coupling) and/or the vertical oceanic resolution (31 vs. 301 levels) in the CGCM. Although the summer mean tropical climate is reasonably well captured with all the configurations of the CGCM and is not significantly modified by changing the frequency of SST coupling from once to twelve per day, the ISM-ENSO teleconnections are rather poorly simulated in the two simulations in which SST is exchanged only once per day, independently of the vertical oceanic resolution used in the CGCM. Surprisingly, when 2 h SST coupling is implemented in the CGCM, the ISM-ENSO teleconnection is better simulated, particularly, the complex lead-lag relationships between the two phenomena, in which a weak ISM occurs during the developing phase of an El Niño event in the Pacific, are closely resembling the observed ones. Evidence is presented to show that these improvements are related to changes in the characteristics of the model's El Niño which has a more realistic evolution in its developing and decaying phases, a stronger amplitude and a shift to lower frequencies when a 2-hourly SST coupling strategy is implemented without any significant changes in the basic state of the CGCM. As a consequence of these improvements in ENSO variability, the lead relationships between Indo-Pacific SSTs and ISM rainfall resemble the observed patterns more closely, the ISM-ENSO teleconnection is strengthened during boreal summer and ISM rainfall power spectrum is in better agreement with observations. On the other hand, the ISM-IOD teleconnection is sensitive to both SST coupling frequency and the vertical oceanic resolution, but increasing the vertical oceanic resolution is degrading the ISM-IOD teleconnection in the CGCM. These results highlight the need of a proper assessment of both temporal scale interactions and coupling strategies in order to improve current CGCMs. These results, which must be confirmed with other CGCMs, have also important implications for dynamical seasonal prediction systems or climate change projections of the monsoon. © 2011 Springer-Verlag. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/55203
Appears in Collections: 过去全球变化的重建
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作者单位: LOCEAN/IPSL, CNRS/IRD/UPMC/MNHN, Université Pierre et Marie Curie, BP100, 4 Place Jussieu, 75252 Paris Cedex 05, France; Indian Institute of Tropical Meteorology, Pune, India; RIGC, Yokohama, Japan
Recommended Citation:
Terray P.,Kamala K.,Masson S.,et al. The role of the intra-daily SST variability in the Indian monsoon variability and monsoon-ENSO-IOD relationships in a global coupled model[J]. Climate Dynamics,2012-01-01,39(3)