鄂北短时强降水特征及双偏振雷达预警指标OA
Characteristics of Short-Duration Heavy Rainfall and Early Warning Indicators with Dual-Polarization Radar in Northern Hubei
利用湖北省随州市逐小时降水以及双偏振雷达观测资料,统计分析2019-2023年短时强降水的分布和双偏振雷达参数特征.结果表明:(1)短时强降水集中在6-8月,6-7月频次较多;日变化特征呈三峰型分布,最多出现在5-8时,其次是22时—次日1时,第三是13-18时.南部较中北部更易出现短时强降水,随县南部是短时强降水高发区.(2)组合反射率因子(CR)、垂直液态水含量(VIL)、2.5 km以下水平反射率因子(ZH)、差分传播相移率(KDP)、差分反射率因子ZDR和回波顶高(ET)与雨强呈正相关.雨强越大,回波强度越强,低层液态粒子浓度越大,回波顶高越高,粒子直径越大.相关系数和最大回波高度与雨强相关性不明显.(3)粒子直径在20～30 mm·h-1和30～40 mm·h-1无明显差异,在40 mm·h-1以上有明显增大.KDP中位数和平均值在≥50 mm·h-1有跃增现象,表明低层液态粒子浓度有明显增大.(4)CR、ET、VIL以及低层ZH、ZDR、KDP预警阈值增幅在20～30 mm·h-1和30～40 mm·h-1不明显,在40 mm·h-1以上较明显.
Using hourly precipitation data and dual-polarization radar observations from 2019 to 2023 in Suizhou City,Hubei Province,this study statistically analyzes the distribution of short-duration heavy rainfall and the characteristics of dual-polarization radar parameters.The results show that:(1)Short-duration heavy rainfall is concentrated from June to August,with the highest frequency in June and July.Diurnally,it exhibits a triple-peak pattern:the primary peak occurs from 05:00 to 08:00BT followed by a secondary peak from 22:00 to 01:00(the next day),and a tertiary peak from 13:00 to 18:00.Spatially,the southern part of the region is more prone to short-duration heavy rainfall than the central and northern parts,with southern Suixian County being the high-frequency center.(2)Radar parameters exhibiting high positive correlations with rainfall intensity include composite reflectivity(CR),vertically integrated liquid(VIL),and horizontal reflectivity(ZH)and specific differential phase(KDP)at heights below 2.5 km.Differential reflectivity(ZDR)and echo top(ET)also show moderate positive correlations.This indicates that more intense rainfall is associated with stronger radar echoes,higher concentrations of liquid hydrometeors at low levels,higher echo tops,and larger diameters of oblate liquid particles.In contrast,the correlation coefficient(CC)and the maximum echo height show no significant correlation with rainfall intensity.(3)The inferred particle size shows no significant difference between rainfall intensity ranges of 20-30 mm·h-1 and 30-40 mm·h-1,but increases markedly for intensities above 40 mm·h-1.Both the median and mean KDP values exhibit a sharp jump at intensities≥50 mm·h-1,indicating a significant increase in the concentration of liquid hydrometeors at low levels.(4)The increasing trends of the early warning thresholds for CR,ET,VIL,and for ZH,ZDR,and KDP at low levels are not pronounced between the 20-30 mm·h-1 and 30-40 mm·h-1 intensity ranges,but become more substantial above 40 mm·h-1.
贺晓露;秦幼文;李格;郝元甲;杨涛
随州市气象局,湖北 随州 441300随州市气象局,湖北 随州 441300随州市气象局,湖北 随州 441300随州市气象局,湖北 随州 441300随州市气象局,湖北 随州 441300
天文与地球科学
短时强降水分布特征偏振参量预警阈值
short-duration heavy rainfalldistribution characteristicspolarization parameterswarning threshold
《沙漠与绿洲气象》 2026 (1)
100-106,7
2022年湖北省气象局面上项目(2022Y20)
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