ENSO hindcast skill of the IAP-DecPreS near-term climate prediction system: comparison of full-field and anomaly initialization

• Published in: Atmospheric and oceanic science letters = Daqi-he-haiyang-kexue-kuaibao Vol. 11; no. 1; pp. 54 - 62
• Main Authors: SUN, Qian, WU, Bo, ZHOU, Tian-Jun, YAN, Zi-Xiang
• Format: Journal Article
• Language: English
• Published: Beijing Taylor & Francis 02.01.2018; KeAi Publishing Communications Ltd; Elsevier; KeAi Communications Co., Ltd
• Subjects: Anomalies; anomaly initialization; Atmospheric circulation; Atmospheric physics; Climate prediction; coupled general circulation model; Data collection; El Nino; El Nino phenomena; ENSO prediction; ENSO预测; full-field initialization; General circulation models; La Nina; Near-term climate prediction system; Ocean currents; Oceanic analysis; Physics; Sea surface; Sea surface temperature; Southern Oscillation; 全场初始化; 异常场初始化; 耦合环流模式; 近期气候预测系统
• ISSN: 1674-2834; 2376-6123
• DOI: 10.1080/16742834.2018.1411753

Model initialization is a key process of climate predictions using dynamical models. In this study, the authors evaluated the performances of two distinct initialization approaches-anomaly and full-field initializations-in ENSO predictions conducted using the IAP-DecPreS near-term climate prediction system developed by the Institute of Atmospheric Physics (IAP). IAP-DecPreS is composed of the FGOALS-s2 coupled general circulation model and a newly developed ocean data assimilation scheme called 'ensemble optimal interpolation-incremental analysis update' (EnOI-IAU). It was found that, for IAP-DecPreS, the hindcast runs using the anomaly initialization have higher predictive skills for both conventional ENSO and El Niño Modoki, as compared to using the full-field initialization. The anomaly hindcasts can predict super El Niño/La Nina 10 months in advance and have good skill for most moderate and weak ENSO events about 4-7 months in advance. The predictive skill of the anomaly hindcasts for El Niño Modoki is close to that for conventional ENSO. On the other hand, the anomaly hindcasts at 1- and 4-month lead time can reproduce the major features of large-scale patterns of sea surface temperature, precipitation and atmospheric circulation anomalies during conventional ENSO and El Niño Modoki winter.