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doi:  10.12013/qxyjzyj2016-026
江西省北部地区一次致灾冰雹天气环境条件和特征分析

Analysis on Environmental Conditions and Characteristics of a Disastrous Hail Event in Northern of Jiangxi
摘要点击 470  全文点击 276  投稿时间:2016-06-20  修订日期:2016-07-22
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基金:  2016年省气象局预报员专项“2015年汛期赣北两次强对流过程对比分析研究”; 2015年省局重点项目“强对流天气的格点化预报方法研究”; 江西省气象局强对流创新团队项目(编号: JXQDL20140010)
中文关键词:  冰雹天气,环境条件分析,卫星TBB, 雷达回波
英文关键词:  hail weather  environment condition analysis  satellite TBB analysis  radar echo characteristic
           
作者中文名作者英文名单位
盛志军Sheng Zhijun江西省气象台, 江西 南昌 300096
邓超Deng Chao成都信息工程大学 大气科学学院, 四川 成都 610225
周雨Zhou Yu江西省气象服务中心, 江西 南昌 330096
朱星球Zhu Xingqiu江西省气象台, 江西 南昌 300096
引用:盛志军,邓超,周雨,朱星球.2016,江西省北部地区一次致灾冰雹天气环境条件和特征分析[J].气象与减灾研究,39(3):190-197
中文摘要:
      利用常规气象观测资料、天气雷达资料、FY-2E卫星TBB资料和NCEP 1°×1°再分析等资料,对2015年4月2日发生在江西省北部地区的冰雹强对流天气环境条件和特征进行了分析。结果表明: 1) 高空槽、低层切变线和地面锋面共同影响,导致此次冰雹强对流天气过程,冷锋及其附近的中尺度地面辐合线是主要触发系统。2) 降雹前6—12 h,江西省北部地区对流层中低层西南风速跃增,并且500 hPa高度层存在干急流轴,干空气卷入能使雨滴脱离上升气流,减弱雨滴的拖曳作用,形成“上干冷、下暖湿”对流不稳定温湿层结。3) 江西省北部地区边界层有假相当位温能量锋区维持;且处于水汽通量辐合区中心,低层维持较强水汽辐合和输送,为冰雹云内雹胚的形成和生长提供了充足的水汽条件。4) 风暴单体具有有界弱回波区、高悬的强反射率因子、强回波伸展至-20 ℃层高度之上、高VIL密度、强中气旋等大冰雹回波特征。TBB分布反映了一个MCS的演变,降雹地点与TBB小于-52 ℃的冷云区及其北侧TBB大梯度区对应较好。
Abstract:
      A hail event occurred in the northern Jiangxi in the afternoon of April 2, 2015 is analyzed with conventional upper air data, automatic weather station data, Nanchang Doppler radar data, images from FY 2E satellite TBB and NCEP 1 °×1° reanalysis data. The results show that this hail event was triggered by the upper trough, low level shear line and the ground front together. Cold front and the mesoscale convergence line were the main trigger systems. The wind speed in the lower troposphere in the northern Jiangxi increased rapidly 6 to 12 hours before the hail dropping. The dry jet stream located at northern Jiangxi in front of the 500hPa trough. Dry air can be involved in the rain from the rising air, weaken the drag of the rain, and form the unstable convective stratification of “dry cold air upper and warm wet air down”. A pseudo equivalent potential temperature energy front maintained in the boundary layer in northern Jiangxi, in which was the water vapor convergence center. In the low layer, strong water vapor convergence and transportation remained, which provided adequate moisture conditions for the formation of hail cloud and hail embryo growth. Some characteristics of large hail echoes were found on the radar echo images, such as BWER, high hanging strong reflectivity, strong echo stretching up to -20 ℃ layer height, high VIL density, and a strong mesocyclone. Hail dropping locations were related with the evolution of a MCS , and they corresponded well with cold cloud area below -52 ℃ or the north of large TBB gradient area.
主办单位:江西省气象学会 单位地址:南昌市高新开发区艾溪湖二路323号
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