In practical operations,the judgment of hail size has always been one of the challenges.To distinguish and identify hails of different sizes,44 hail events in Jiangxi from February to May during 2021-2024 were selected based on ground obser-vation data and dual-polarization radar data from Nanchang and Ji'an stations.According to the radar polarization values and their variations at different altitude levels for hail of different sizes in the central-northern regions of Jiangxi Province,the threshold characteristics for distinguishing different sizes of hails were obtained.The results showed that:1)At the same alti-tude level,the larger the hail size,the greater the median ZH value,and the smaller the median ZDR value and CC value.The median difference in ZH values between giant hail and small hail were more than or equal to 10 dBZ in both the near-ground lay-er and the altitude layer above-20 ℃ layer.2)The median ZUR value of small hail below the melting layer was generally posi-tive,the median ZDR value of large hail was close to 0 dB at multiple altitude levels,while the median ZDR value of giant hail was generally negative.The CC value of giant hail below the melting layer was typically less than 0.9.3)Above the-20 ℃ layer,ZH was more sensitive to hail size,while CC and ZDR showed less significant variation.Among-20 and 0 ℃ layer,ZH and CC were more sensitive to hail size,while ZDR showed less variation.Below the melting layer,ZH,CC and ZDR all provided certain indications of hail size.4)The size of hails would be better determined by combining multiple types of polarization pa-rameters.The larger the hail size,the higher the probability of TBSS.The polarization feature of TBSS would be used to iden-tify large hail effectively.
关键词
天气雷达/冰雹尺寸/偏振特征/三体散射/温度层高度
Key words
weather radar/hail size/polarization characteristics/TBSS/height of temperature layer
维普
万方数据