预报技巧的诊断研究

DIAGNOSTIC STUDY ON FORECAST SKILL

中文关键词:  预报技巧  功率谱分析  正压不稳定性

英文关键词:Forecast skill  Power spectrum analysis  Barotropic instability

中文摘要:

      利用国家气象中心(北京)T42L9模式的初始资料和预报资料,对500hPa高度场的预报技巧进行了统计分析,并用一个简单的正压准地转谱模式对两个典型个例的正压不稳定性进行了研究。结果发现:北半球500hPa高度场第五天的预报与初始场的某些经验正交函数的典型场有关。预报技巧与初始场的稳定性及其误差和背景场的配置有关。

英文摘要:

      On the basis of the diagnostic analysis of 500hPa height's initial analysis field and forecast field data of T42L9 model of National Meteorological Center(Beijing), forecast skill of cases has been carefully surveyed using statistic method. Two basic results have been obtained a) The forecasting of forecast skill should be done together with the forecast products abve three-day time level;b) There are some significant periods of day-to-day forecast skill of cases of T42L9 model according to the power spectrum analysis. The correlation analysis show that there are some EOF fields correlating with forecast skill of Northern Hemesphere at five-day time level. A simple barotropic quasi-geostrophic spectrum model is used to examine two typical case's barotropic instability. The results show that forecast skill is associated with the instability of initial field of the model and the allocation of error with background field of the cases.