中文摘要：

大气季节内振荡（ISO）在天气气候演变中扮演着重要角色，是中期和延伸期预报可预报性来源之一，同时大气ISO的年际变化与区域季节降水量的年际变化密切联系，对短期气候预测有指示意义。对热带大气ISO的年际变化研究做了简要回顾；重点介绍了ISO对华南降水的影响及其业务应用情况，主要包括赤道MJO对华南降水的影响、基于准两周振荡的汛期暴雨过程预报、热带ISO与热带外系统多尺度相互作用对强降水的影响、ISO对季节降水的影响、基于／SO建立的降水延伸期定量预测模型；最后对进一步加强ISO应用研究提出了几点思考。

英文摘要：

Atmospheric intraseasonal oscillation （ISO） plays important roles in the evolution of weather and climate. ISO is one of the predictability sources for medium- and extended-range forecast. Moreover, there exists close relationship between ISO and seasonal rainfall in interannual time scale. In this review, the study on the interannual variation of ISO is first introduced briefly, and the impact of ISO on the precipitation over South China and its application in operational forecast is addressed. We focus especially on the impact of MJO on the precipitation over South China, forecast of torrential rain in rainy seasons based on quasi biweekly oscillation, impact of multiple scales interaction between tropical ISO and weather systems outside tropics on severe rain, contribution of ISO to the seasonal precipitation, quantitative precipitation forecasting model for extended-range. Finally, some thinking about further ISO application and research is proposed.