应用IAP9L-AGCM对2002年中国夏季气候的预测及效果检验

Prediction of Summer Climate over China in 2002 with IAP9L-AGCM and Its Performance

利用中科院大气所9层大气环流格点模式(IAP9L-AGCM)和IAP-ENSO预测系统对2002年中国夏季气候进行实时集合预测及其检验。结果显示,IAP9L-AGCM较好地预测出了2002年夏季我国大范围旱涝的分布形势,如华南、我国西部多雨,黄河和长江流域之间大范围干旱等;850hPa减弱的夏季风、青藏高原辐散中心以及北太平洋上空的异常气旋性环流中心亦被较好地预报出来;不足的是,模式对降水异常细致分布的预测能力有限。预测结果还表明,该模式对夏季(6—8月)平均降水的预报技巧要高于月平均状况,且月平均预报的准确度从6—8月依次递减。

By using the IAP 9-level grid-point Atmospheric General Circulation Model (IAP9L-AGCM) and IAP-ENSO forecasting system,developed at the Institute of Atmospheric Physics under the Chinese Academy of Sciences,ensemble predictions of summer climate anomalies over China in 2002 are carried out in this study.Moreover,its performance is evaluated and compared with the observation.It is shown that the predicted pattern of climate anomalies generally agrees well with the observed one over most regions of China,such as positive precipitation anomalies over South and West China,as well as drought over most part of areas between the Yellow River and the Yangtze River valley.In addition,the weakened East Asian summer monsoon at 850hPa,anomalous divergence center over the Qingzang Plateau,and cyclonic circulation anomaly over North Pacific are all well captured.Also,it is revealed that the predicted pattern of summer (JJA mean) rainfall anomalies is more reliable than monthly one,and the prediction skill is gradually decreased through June to August.