Improved ENSO Forecasts by Assimilating Sea Surface Temperature Observations into an Intermediate Coupled Model  

作　　者：郑飞 朱江 Rong-Hua ZHANG 周广庆 

机构地区：[1]International Center for Climate and Environment Science （ICCES）,Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029 [2]Earth System Science Interdisciplinary Center （ ESSIC）, University of Maryland, College Park, Maryland, USA

出　　处：《Advances in Atmospheric Sciences》2006年第4期615-624,共10页大气科学进展（英文版）

基　　金：The research was supported by the Natural Science Foundation of China （Grant Nos. 60225015, 40233033, and 40221503）.

摘　　要：A simple method for initializing intermediate coupled models （ICMs） using only sea surface temperature （SST） anomaly data is comprehensively tested in two sets of hindcasts with a new ICM. In the initialization scheme, both the magnitude of the nudging parameter and the duration of the assimilation are considered, and initial conditions for both atmosphere and ocean are generated by running the coupled model with SST anomalies nudged to the observations. A comparison with the observations indicates that the scheme can generate realistic thermal fields and surface dynamic fields in the equatorial Pacific through hindcast experiments. An ideal experiment is performed to get the optimal nudging parameters which include the nudging intensity and nudging time length. Twelve-month-long hindcast experiments are performed with the model over the period 1984-2003 and the period 1997-2003. Compared with the original prediction results, the model prediction skills are significantly improved by the nudging method especially beyond a 6-month lead time during the two different periods. Potential problems and further improvements are discussed regarding the new coupled assimilation system.A simple method for initializing intermediate coupled models （ICMs） using only sea surface temperature （SST） anomaly data is comprehensively tested in two sets of hindcasts with a new ICM. In the initialization scheme, both the magnitude of the nudging parameter and the duration of the assimilation are considered, and initial conditions for both atmosphere and ocean are generated by running the coupled model with SST anomalies nudged to the observations. A comparison with the observations indicates that the scheme can generate realistic thermal fields and surface dynamic fields in the equatorial Pacific through hindcast experiments. An ideal experiment is performed to get the optimal nudging parameters which include the nudging intensity and nudging time length. Twelve-month-long hindcast experiments are performed with the model over the period 1984-2003 and the period 1997-2003. Compared with the original prediction results, the model prediction skills are significantly improved by the nudging method especially beyond a 6-month lead time during the two different periods. Potential problems and further improvements are discussed regarding the new coupled assimilation system.

关 键 词：ENSO intermediate coupled model prediction skill HINDCAST 

分 类 号：P732.4[天文地球—海洋科学]