对一次局地短时强降水过程的集合预报研究  

Ensemble Forecasting of a Local Short-Lived Severe Precipitation

作　　者：王晨稀[1] 姚建群[2] 

机构地区：[1]中国气象局上海台风研究所,上海200030 [2]上海中心气象台,上海200030

出　　处：《高原气象》2008年第6期1229-1239,共11页Plateau Meteorology

基　　金：国家自然科学基金项目(40605018)资助

摘　　要：以上海区域降水集合预报系统为基础，对2007年6月23～24目发生在上海地区的一次短时强降水过程进行了集合预报研究。结果表明：该集合预报系统总体上对这次强降水过程作出了较好的预报，但对强降水发生的时间、地点的预报还有误差，集合预报提供的概率预报结果比集合平均预报结果更具有参考价值。模式物理过程、初值和侧边界的不确定性对降水预报结果的影响是不同的。对降水结果，模式对流参数化方案的影响非常大，并贯穿于整个积分过程；边界层参数化方案的影响较小；侧边界不确定性的影响在初始阶段较小，随后逐渐增大，积分一定时间后，其影响与对流参数化方案的影响相当；初值不确定性在初始阶段有一定的影响，随后逐渐减小。同时考虑3种不确定性的集合预报效果总体上好于没有考虑侧边界不确定性的集合预报效果，考虑模式物理过程和侧边界不确定性的集合预报效果总体上比考虑3种不确定性的集合预报效果更好。对于考虑模式物理过程和侧边界不确定性的集合预报，改进初值能有效地改进对有无降水的预报，但对强度稍大一些的降水预报没有改进。Based on the operational ensemble forecast system for Shanghai regional precipitation, the ensemble forecasting of a short-lived severe preeipition in Shanghai on 23-24 June 2007 is made. The results show that the precipitation is predicted by the ensemble forecast system, but there is error in predicting the occurring time and loeation. The ensemble probability forecast is more useful and valuable than the ensemble mean forecast. The effects from the model uncertainty, the initial value uncertainty and the lateral boundary uncertainty on precipitation forecast are different. The effect from the model eonvective parameterization scheme is very large, which maintains large during the entire model integration. The effect from the model PBL parameterization scheme is small. During the early period of model integration, the effect from the lateral boundary uncertainty is small. Later, the effect becomes larger and larger. After some time, this effect is as large as the effect from the model convective parameterization scheme. During the early period of model integration, the effect from the initial value uncertainty is obvious. Later, this effect becomes smaller and smaller. The ensemble forecast which contains three kinds of uncertainty is better than the ensemble forecast which does not contain the lateral boundary uncertainty. The ensemble forecast which contains the model uncertainty and the lateral boundary uncertainty is better than the ensemble forecast which contains three kinds of uncertainty. In the ensemble forecasting which contains the model uncertainty and the lateral boundary uncertainty, the improving initial value can improve the ensemble forecast of precipitation of low threshold, but it can not improve the ensemble forecast of precipitation of high threshold.

关 键 词：强降水 集合预报 不确定性 侧边界 

分 类 号：P456[天文地球—大气科学及气象学]