Prediction of Summer Climate Anomaly over China for 1999 and Its Verification
1999年中国夏季气候的预测和检验

In combination with the predicted equatorial Pacific Sea Surface Temperature Anomaly (SSTA) by IAP ENSO prediction system, the summer climate anomalies for year 1999 have been predicted by the improved IAP Prediction System of Short-Term Climate Anomaly (IAP PSSCA). Generally, the predicted pattern of the general circulation anomaly (e.g., 500 hPa geopotential height) agrees well with the observation. As for the prediction result for 1999 summer monsoon rainfall anomaly, verification map shows that, for the JJA mean, the positive rainfall anomalies over the Yangtze River valley, South China have been well predicted by IAP PSSCA, and the drought over most part of North China have also been predicted, although the detailed rainfall anomaly distribution has some discrepancies compared with the observation, especially over North China. As for monthly mean pattern of the rainfall anomaly, the uncertainties of the prediction and its disagreement with the observation are both relatively large compared with that in seasonal time scale, and this is due to the limitation of current seasonal to extraseasonal climate prediction system. All above results indicate that, although IAP PSSCA does show some skill in the prediction of summer monsoon rainfall anomaly over China, further improvements in this system are still needed.