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江苏地区降水预报订正研究

2021-07-17梅钦盛也高雅裔传祥

河南科技 2021年7期

梅钦 盛也 高雅 裔传祥

摘 要:本文选取2017—2019年欧洲中心数值预报产品(European Centre for Medium-Range Weather Forecasts,ECMWF)模式,利用频率匹配和消空订正的方法对江苏及周边地区24~96 h数值预报产品和对应的区域自动站数据进行客观订正。结果表明,单一的频率匹配方法对降水预报提高有限,但在此基础上采用消空订正方法,可以明显提高降水预报准确率。具体表现为24 h预报时效的晴雨预报准确率提高24%,小雨TS评分提高30%,暴雨TS评分提高2.4%,均方根误差减少2%,距平相关系数提高了1.4%。

关键词:降水预报;频率匹配;消空订正

中图分类号:P456文献标识码:A文章编号:1003-5168(2021)07-0132-03

Research on the Correction of Precipitation Forecast in Jiangsu

MEI Qin SHENG Ye GAO Ya YI Chuanxiang

(Yancheng Meteorological Service,Yancheng Jiangsu 224000)

Abstract: This paper selected European Center for medium-range weather forecasts (ECMWF) model from 2017 to 2019, used frequency matching and spaced elimination correction method to make objective correction for 24~96 h numerical forecast products and corresponding regional automatic weather station data in Jiangsu and its surrounding areas, and used frequency matching and space elimination correction method. The results show that a single frequency matching method can only improve the accuracy of precipitation forecasting, but on this basis, the threshold method can significantly improve the accuracy of precipitation forecasts. Specifically, the accuracy of sunny and rainy forecasts increased by 24 %, the TS score for light rain increased by 30 %, the TS score for heavy rain increased by 2.4 %, the root mean square error was reduced by 2 %, and the anomaly correlation coefficient increased by 1.4 %.

Keywords: precipitation forecast;frequency matching method;threshold

近年来,随着数值天气预报技术的飞速发展,数值模式产品的预报能力不断提高,模式产品已经成为预报员们制作日常天气预报的主要参考[1]。然而,大气的非线性变化、模式参数化方案近似值和初值的不确定性,降水特殊的不连续性和非正态分布的特征,导致预报难度增大。因此,在现有模式预报基础上,通过统计订正的方法,消除部分系统偏差,提高预报准确率是非常有必要的。降水是公众和政府部门最为关心的气象预报要素之一,因此,提高降水预报准确率是气象研究工作者一直钻研的方向。目前,国内外已经有大量学者在相关方面展开研究[2-3],其中,通过样本统计方法进行模式数据的订正已经被广泛应用于降水预报研究中。智协飞等人[4]和王姝苏等人[5]对全国大范围的降水订正进行了研究,结果发现,统计订正法可以提高降水准确率,减少空报率和漏报率。……

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