近10a海南岛冰雹天气统计特征与概念模型

Statistical characteristics and conceptual model of hail weather in Hainan Island during recent 10years

利用常规资料和海口多普勒雷达资料对2004-2014年海南岛出现的22次冰雹过程进行统计分析。结果表明:海南岛冰雹均出现在春季;冰雹落区集中在东方-琼中-琼海一线的五指山以北地区;按照影响系统可分为西南低压槽Ⅰ型、西南低压槽Ⅱ型、东路冷空气型和西路冷空气型;西南低压槽Ⅰ型冰雹落区在儋州和澄迈,西南低压槽Ⅱ型落区较分散,二者出现的时间集中在14:00-17:00;冷空气型冰雹发生时间与锋面到达时间密切相关,西路冷空气型冰雹落区集中在东方和昌江,东路冷空气型则在海口、临高和文昌;西南低压槽Ⅰ型湿层可达对流层上层,具有强热力条件,触发机制为海陆风辐合线;西南低压槽Ⅱ型和冷空气型600-500 h Pa有明显干区,边界层华南沿海至海南岛北部地区有冷式切变;0℃层高度集中在4.3-5.1 km,-20℃层高度为7.6-8.4 km;冰雹直径与低层垂直风切变大小有一定的正相关;直径大于等于20 mm的大冰雹△T850-500≥27℃;基于海口多普勒雷达提炼的海南岛冰雹临近预报指标为最大组合反射率CR≥55 d BZ,50 d BZ强回波高度达到-20℃层,最大垂直液态水含量VIL值≥60 kg·m-2,回波顶高ET≥15km。

Based on the conventional data and Doppler radar data from 2004 to 2014 in the Hainan Island, 22 hail processes were analyzed. The results show that： hail of Hainan appear in the spring;dropping zone concentrated in the north area of Wuzhishan（ Donggfang- Qiong Zhong- Qonghai line）; According to the affecting system, the hail weather can be divided into four types： southwest trough Ⅰ, southwest trough Ⅱ, east road of cold air and west road of cold air; hail of southwest trough type Ⅰdrops in Danzhou and Cheng Mai, dropping zone of southwest trough type Ⅱ is dispersed, both of these two types of hail appearing time is on PM 14：00- 17：00; Cold air type hail occurrence time is closely related to the frontal arrival time, the dropping zone of west road of cold air type hail concentrates in the Dongfang and Chang Jiang, while the east road of cold air located in Haikou, Lingao and Wenchang; wet layer of southwest trough type Ⅰ could be up to the upper troposphere with strong thermal conditions and the solar wind convergence line as the triggering mechanism; There is obvious dry area in 600-500 h Pa of southwest trough Ⅱ type and cold air type, and cooled shear in the boundary layer of the coastal areas in south China and the north of Hainan island; the height of 0 ℃ layer is concentrated in 4.3 to 5.1 km, and-20 ℃ layer height is 7.6 to 8.4 km; The diameter size of hail and lower vertical wind shear has certain positive correlation; the big hail with its diameter over or equaling to 20 mm, the△T850-500 is over or equal to 27 ℃; the hail forecasting indexes, which is extracted from Doppler radar data in Haikou, is the maximum CR over or equaling to 55 dBZ, strong echo of 50 dBZ reaching- 20 ℃ layer height, maximum vertical liquid water content VIL ≥60 kg · m- 2, high echo top ET ≥15 km.