Forecasts of South China Sea surface temperature anomalies using the Nio indices and dipole mode index as predictors

IOCAS-IR

	Forecasts of South China Sea surface temperature anomalies using the Nio indices and dipole mode index as predictors
	Chen HY(陈海英); Fang GH(方国洪); Yin BS(尹宝树); Wang YG(王永刚); Wei ZX(魏泽勋)
发表期刊	Chinese Journal of Oceanology and Limnology
ISSN	0254-4059
	2010-02-15
出版年	2010
卷号	v.28 期号:01 页码:146-154
文献类型	CNKI期刊论文
摘要	Based on an empirical orthogonal function (EOF) analysis of the monthly NCEP Optimum Interpolation Sea Surface Temperature (OISST) data in the South China Sea (SCS) after removing the climatological mean and trends of SST,over the period of January 1982 to October 2003,the corresponding TCF correlates best with the Dipole Mode Index (DMI),Nio1+2,Nio3.4,Nio3,and Nio4 indices with time lags of 10,3,6,5,and 6 months,respectively.Thus,a statistical hindcasts in the prediction model are based on a canonical correlation analysis (CCA) model using the above indices as predictors spanning from 1993/1994 to 2003/2004 with a 1-12 month lead time after the canonical variants are calculated,using data from the training periods from January 1982 to December1992.The forecast model is successful and steady when the lead times are 1-12 months.The SCS warm event in 1998 was successfully predicted with lead times from 1-12 months irrespective of the strength or time extent.The prediction ability for SSTA is lower during weak ENSO years,in which other local factors should be also considered as local effects play a relatively important role in these years.We designed the two forecast models:one using both DMI and Nio indices and the other using only Nio indices without DMI,and compared the forecast accuracies of the two cases.The spatial distributions of forecast accuracies show different confidence areas.By turning off the DMI,the forecast accuracy is lower in the coastal areas off the Philippines in the SCS,suggesting some teleconnection may occur with the Indian Ocean in this area.The highest forecast accuracies occur when the forecast interval is five months long without using the DMI,while using both of Nio indices and DMI,the highest accuracies occur when the forecast interval time is eight months,suggesting that the Nio indices dominate the interannual variability of SST anomalies in the SCS.Meanwhile the forecast accuracy is evaluated over an independent test period of more than 11 years (1993/94 to October 2004) by comparing the model performance with a simple prediction strategy involving the persistence of sea surface temperature anomalies over a 1-12 month lead time (the persisted prediction).Predictions based on the CCA model show a significant improvement over the persisted prediction,especially with an increased lead time (longer than 3 months).The forecast model performs steadily and the forecast accuracy,i.e.,the correlation coefficients between the observed and predicted SSTA in the SCS are about 0.5 in most middle and southern SCS areas,when the thresholds are greater than the 95% confidence level.For all 1 to 12 month lead time forecasts,the root mean square errors have a standard deviation of about 0.2.The seasonal differences in the prediction performance for the 1-12 month lead time are also examined.
关键词	forecast sea surface temperature anomaly (SSTA) canonical correlation analysis (CCA) Nio indices dipole mode index (DMI)
CNKI专辑号	A;
CNKI专辑名称	基础科学;
CNKI专题号	A010
CNKI专题名称	海洋学;
分类号	P731.11
收录类别	中科院核心
语种	英文;
资助项目(基金）	Supported by National Natural Science Foundation of China (No. 40706011) ; the Key Program of Knowledge Innovation Project of Chinese Academy of Sciences (No. KZCX1-YW-12) ; the National Science Foundation of China (Nos. 405201 and 40074) ; the International Cooperative Program of the Ministry of Science and Technology (No. 2006DFB21630) ; by the Open Foundation of Key Laboratory of Marine Science and Numerical Modeling (MASNUM)
文献类型	CNKI期刊论文
条目标识符	http://ir.qdio.ac.cn/handle/337002/192247
专题	中国科学院海洋研究所
作者单位	1.KeyLaboratoryofOceanCirculationandWave,InstituteofOceanology,ChineseAcademyofSciences 2.KeyLaboratoryofMarineScienceandNumericalModeling,theFirstInstituteofOceanography,SOA
推荐引用方式 GB/T 7714	Chen HY,Fang GH,Yin BS,et al. Forecasts of South China Sea surface temperature anomalies using the Nio indices and dipole mode index as predictors. 2010.