长江中下游汛期降水模式预测误差相似性及其可预报度  

The analogy and predictability of the forecasting model error for the precipitation over the mid-lower reaches of the Yangtze River in summer

作　　者：王启光[1] 苏海晶[2,3] 支蓉 冯爱霞[4] 

机构地区：[1]中国气象局气象干部培训学院,北京100081 [2]国家气候中心预测室,北京100081 [3]扬州大学物理科学与技术学院,扬州225002 [4]国家气象信息中心,北京100081

出　　处：《物理学报》2014年第11期435-443,共9页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:41305100和41105055);公益性行业科研专项(批准号:GYHY201306021);全球变化重大研究计划(批准号:2012CB955902)资助的课题~~

摘　　要：对数值模式预测误差进行相似预报进而订正模式预报结果,是提高模式预报水平的有效手段之一.本文从数值模式预测误差场存在相似性的角度出发,研究了长江中下游汛期降水逐年模式误差场间的相似性及其可预报性,探讨了数值模式预测误差在历史资料中的相似信息量,发现利用相似误差订正可以明显提高模式预报水平.进一步对历史模式预测误差场进行经验正交函数(EOF)分解,着重研究了误差场前三个特征向量的空间分布及其时间系数演化规律,发现对各分量分别进行相似预报可以简化预报对象,并且针对性更强,可以提高其潜在预报水平.在研究数值模式预测误差场相似性的基础上,定义了数值模式预测误差的相似可预报度,用以衡量逐年模式预测误差的可预测性,发现模式预测误差场前三个分量的相似可预报度明显高于原始模式误差场,揭示出有针对性地分别预报模式预测误差各分量的潜在应用价值.This paper reports an effective method to improve the forecasting level of the numerical model through analogue prediction of errors and correction of the results. The analogy of the precipitation model errors and its predictability are studied for the mid-lower reaches of the Yangtze River in summer time in the perspective of analogy, which exists in the error field in the forecasting numerical model. The content of the analogy is also investigated according to the historical data. It is found that the forecasting errors could be improved remarkably by analogue error prediction over the regions researched in summer time. The forecasting error field is decomposed by EOF, and then the geographic distribution and time coefficient evolution of the first three principal components are analyzed. The prediction of the precipitation could be simplified by analogue forecasting of the principal components separately, and it is more targeted to improve the potential forecasting level. On the basis of the analogy of the forecasting error field, its analogue predictability is defined to measure the predictability of the errors. The analogue predictability of the first three principal components is significantly higher than that of the original field. It has potential applications to precipitation predication by forecasting the error field principal components.

关 键 词：汛期降水 模式预测误差 相似性 可预报度 

分 类 号：P457.6[天文地球—大气科学及气象学]