基于增长模繁殖法的暴雨集合预报  

Storm ensemble forecast based on the BGM method

作　　者：闵锦忠[1] 房丽娟[1] 

机构地区：[1]南京信息工程大学气象灾害教育部重点实验室,江苏南京210044

出　　处：《大气科学学报》2017年第1期1-12,共12页Transactions of Atmospheric Sciences

基　　金：国家自然科学基金重点资助项目(41430427);南京信息工程大学人才启动经费项目(2014g109)

摘　　要：采用WRF模式对2010年9月发生在河南省附近的一次暴雨过程进行了集合预报试验。用增长模繁殖方法(BGM)制作了集合预报方案1;为了充分利用背景场信息,结合时间滞后法,制定了集合预报方案2:滚动繁殖法;考虑到暴雨过程中天气形势的特殊性,结合区域空间特征,制定了集合预报方案3:区域繁殖法。这3组试验均对变量U、V、T、Q进行了初值扰动,加上控制预报,均产生了9个集合成员。试验结果表明:几种集合预报方法在预报效果上相较于控制预报都具有明显的改善,滚动繁殖法及区域繁殖法对增长模繁殖法都具有一定的改进作用,其中区域繁殖法的预报效果更优,与实况更为接近。Rainstorms frequently occur in China, resulting in significant loss of economic assets.For this reason, meteor- ologists throughout the country have performed great amounts of research regarding rainstorm prediction.Although the synoptic-scale evolution of the typical mid-latitude weather system is relatively well forecasted, numerical weather prediction models still face many difficulties in forecasting the storm-scale details.The storm-scale numer- ical weather predictions have significant limitations, e.g.the development process of medium-scale and micro-scale systems is sensitive to the physical and boundary layer processes, which are responsible for forecast uncertainty; and the chaotic characteristics and nonlinear action of the atmosphere result in predictability limitations.Consider- ing both the problems described above and the successful application of an ensemble forecast technique for global medium-scale forecasts,it is reasonable to choose an ensemble forecast.In comparison with a single control fore- cast,an ensemble forecast can provide a more accurate estimate of the first moment of the probability density function of future atmospheric states, and can also provide higher-order moment estimations, such as the forecast error variance.How to obtain fast-growth errors ,which is comparable to the actual forecast growth error,is an im- portant problem involved in ensemble forecast. In order to obtain the actual fast-growth errors, the Breeding of Growth Mode （BGM） has been used in this paper.The method,proposed by Toth and Kalnay（1997） ,which has been used to generate perturbations for medium-scale ensemble forecast at NCEP,is a reasonable choice for cap- turing growing errors modes ,especially with extreme weather.There are some problems to be solved when genera- ting initial perturbation with BGM, such as the number of ensemble members, breeding cycles, and time span.It has been demonstrated that the number of BGM ensemble members should be no less than eight, thus in this paper nine was chos

关 键 词：集合预报 暴雨 增长模繁殖法 

分 类 号：P457.6[天文地球—大气科学及气象学]