The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes

doi:10.1175/JCLI-D-17-0623.1

	The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes
	Li, Yuanlong 1,2,3; Han, Weiqing 2; Wang, Wanqiu 4; Zhang, Lei 2; Ravichandran, M.5
刊名	JOURNAL OF CLIMATE
	2018-07-01
卷号	31 期号:14 页码:5351-5370
关键词	Monsoons Sea Surface Temperature Air-sea Interaction Forecasting Intraseasonal Variability
ISSN号	0894-8755
DOI	10.1175/JCLI-D-17-0623.1
文献子类	Article
英文摘要	Northward-propagating Indian summer monsoon intraseasonal oscillations (MISOs) are a major origin of the active-break spells of the monsoon rainfall. Forecast results for 28 active and 27 break spells from the National Centers for Environmental Prediction (NCEP) Climate Forecast System, version 2 (CFSv2), during 1999-2010 are analyzed. CFSv2 forecasts are able to represent the propagation of MISOs from the equator to central India, showing improvements in many aspects compared to its previous version. Systematic biases for MISOs, however, still exist, exhibiting apparently weaker amplitude and slower northward propagation compared to observations. The eastern Arabian Sea (EAS)-western Bay of Bengal (WBB) region (EAS-WBB region; 12 degrees-20 degrees N, 65 degrees-85 degrees E) is found to be critical for the MISO prediction. In that region, the forecast and observed MISO trajectories begin to bifurcate from each other, and forecast errors grow rapidly. Further diagnosis reveals that local air-sea interaction in that region is severely underrepresented in CFSv2. Sea surface temperature (SST) response to surface heat flux forcing and convection response to SST forcing are both too weak, leading to the underestimated MISO amplitude. The relationship between precipitation and SST in CFSv2 is much more chaotic than in observation. The misrepresentation of air-sea coupling results in longer MISO periods in the EAS-WBB region, manifesting as slower propagation and delayed arrival of MISOs in central India. Refining the air-sea coupling processes is crucial for improving the CFSv2 forecast. This includes taking into account the ocean skin layer, better resolving the diurnal cycle, and improving the ocean model physics.
WOS关键词	SYSTEM VERSION 2 ; SURFACE TEMPERATURE VARIABILITY ; BENGAL SALINITY STRATIFICATION ; OCEAN-ATMOSPHERE INTERACTION ; TROPICAL WESTERN PACIFIC ; DIURNAL CYCLE ; NORTHWARD PROPAGATION ; SST VARIABILITY ; SOLAR-RADIATION ; COUPLED MODEL
WOS研究方向	Meteorology & Atmospheric Sciences
语种	英语
出版者	AMER METEOROLOGICAL SOC
WOS记录号	WOS:000435075300002
资助机构	Earth System Science Organization, Ministry of Earth Sciences, government of India(SSC-03-002 ; National Natural Science Foundation of China (NSFC)(41776001) ; NSF(OCE-1658132) ; MM/SERP/CNRS/2013/INT-10/002)
内容类型	期刊论文
源URL	[http://ir.qibebt.ac.cn/handle/337004/11387]
专题	中国科学院青岛生物能源与过程研究所
通讯作者	Li, Yuanlong
作者单位	1.Chinese Acad Sci, Inst Oceanol, Key Lab Ocean Circulat & Waves, Qingdao, Peoples R China 2.Univ Colorado, Dept Atmospher & Ocean Sci, Boulder, CO 80309 USA 3.Qingdao Natl Lab Marine Sci & Technol, Funct Lab Ocean Dynam & Climate, Qingdao, Peoples R China 4.NOAA, Climate Predict Ctr, NWS, NCEP, College Pk, MD USA 5.Natl Ctr Antarctic & Ocean Res, Vasco De Gama, India
推荐引用方式 GB/T 7714	Li, Yuanlong,Han, Weiqing,Wang, Wanqiu,et al. The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes[J]. JOURNAL OF CLIMATE,2018,31(14):5351-5370.
APA	Li, Yuanlong,Han, Weiqing,Wang, Wanqiu,Zhang, Lei,&Ravichandran, M..(2018).The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes.JOURNAL OF CLIMATE,31(14),5351-5370.
MLA	Li, Yuanlong,et al."The Indian Summer Monsoon Intraseasonal Oscillations in CFSv2 Forecasts: Biases and Importance of Improving Air-Sea Interaction Processes".JOURNAL OF CLIMATE 31.14(2018):5351-5370.