风廓线雷达资料在江西梅雨锋暴雨天气过程中的分析应用

Analysis and Application of Wind Profiler Radar Data in a Meiyu Front Rainstorm Weather Process in Jiangxi

利用宜春站风廓线雷达资料和区域自动站降水资料,对2014年6月19—22日江西省持续性暴雨天气过程进行了分析。结果发现:1)1—2.5 km高度的西南急流增强或减弱与下游降水的增强或减弱有较好相关性,其中,较低层1—1.5 km高度的西南急流增强与下游降水增强关系更为密切;1—3.5 km高度的西南急流增强且风速大于12 m/s的较强急流向下层传递,与下游降水增强有较好对应关系,且对降水加强指示提前量约为2 h。2)1 km高度以下的水平风在垂直方向上的风切变(△V)增大为8 m/s以上有利于下游降水增强,当△V为12—20 m/s时,降水明显增强,且△V增大较降水增强提前1—3 h;1 km或0.7 km高度以下△V的增大与下游降水的增强关系较为密切,而1 km或0.7 km高度以上△V增大与下游降水增强关系并不明显。3)指数M、I的大小与下游区域降水量总体呈正相关关系。当指数M、I增大至峰值,且急流指数脉动增强、频率增大时,下游区域降水也将出现峰值,且指数峰值出现较降水峰值提前1—3 h。4)0.5—2.5 km高度的暖平流增强,暖平流的厚度越大,且暖平流之上伴有冷平流加强,越有利于下游区域降水增强;2 km高度以下暖平流逐渐减弱,对应下游区域降水也逐渐减弱;1 km高度以下由冷平流控制,降水则减弱停止。

Based on the wind profile radar data in Yichun and meso-scale weather station data,a continuous rainstorm process during 19-22 June 2014 was analyzed.The conclusions were as follows:1)There was a positive correlation between evolving of southwest jet at height of 1-2.5 km and downstream precipitation,especially for the southwest jet at height of 1-1.5 km.Growing of southwest jet at height of 1-3.5 km and downward transferring of the jet more than 12 m/s had a good corresponding relationship to the growing of downstream precipitation.The change of jet advanced to precipitation strengthening was about 2 hours.2)Downstream precipitation enhanced when △V below1 km increased to above 8 m/s.Precipitation increased obviously when △V was 12-20 m/s.Growing of△V below1 km or 0.7 km was closely related to growing of downstream precipitation,but growing of△Vabove 1 km or 0.7 km was different.The change of△V was 1-3 hours ahead of the grow-ing of downstream raining.3)There was a positive correlation between indexes M or I and downstream rainfall.When the indexes M or I grew to their peaks with stronger pulsation and larger frequency,downstream raining would grow to its peak1-3 hours later.4)The downstream precipitation increased with the enhancements of warm advection at 0.5-2.5 km and cold advection above the warm advection.When the warm advection at 0.5-2.5 km subsided,the corresponding downstream raining faded.Especially when cold advection occupied below1 km,raining faded to end.