珠三角地区前汛期强对流天气环境参数分析

An Analysis of the Parameters of the Environment for Severe Convective Weather in the Annually First Rainy Season of Pearl River Delta Area

基于2016年3-6月前汛期强对流天气过程和高空探测资料,采用方差分析等统计方法对强对流天气发生前各物理量指标进行对比分析。结果表明,水汽方面,广东省前汛期短时强降水对低层以及整层水汽有着更高的要求,雷暴大风和冰雹的中高层水汽较短时强降水显著减少42.4%和48.9%。层结稳定度方面,冰雹的SI指数和LI指数较短时强降水和雷暴大风显著增加135.8%、51.9%和62.8%、43.8%。能量方面,冰雹的CAPE值较短时强降水和雷暴大风显著增加39.6%和55.9%。雷暴大风的NCAPE值和DCAPE_(600)值比短时强降水显著增加15.5%和25.3%,冰雹的DCAPE_(600)值更高,比雷暴大风显著高15%。动力方面,冰雹的Wsr_( 0-6)指数和SRH较短时强降水和雷暴大风分别显著增加15.5%、34.7%和24.5%、55.5%,雷暴大风和冰雹的EHI值比短时强降水的高40.9%和138.0%。冰雹的Z_0和Z_(-20)较短时强降水显著下降4.3%和6.4%。

Based on the processes of severe convective weather in the annually first rainy season from March to June 2016 and associated upper-level radiosonde data, this paper compares and analyzes the indexes of different physical quantities prior to their occurrence using statistical methods such as variational analysis. The result is shown as follows. Short-term severe rain during the rainy season consumes a large amount of water vapor in the low level and throughout the whole column of the atmosphere so that water vapor is 42.4% and 48.9% respectively less in the mid-and upper-level during thunderstorms and hails as compared with short-term severe rain. For stratification stability, the SI and LI of hail are 135.8% and 51.9% more than that of short-term severe rain, respectively, and 62.8% and 43.8% more than that of thunderstorm, respectively. For energy, the CAPE value of hail is 39.6% and 55.9% more than that of short-term severe rain and thunderstorm, respectively. The NCAPE and DCAPE600 values of thunderstorm are 15.5% and 25.3% more than that of short-term severe rain, respectively, and the value of hail is even higher, 15% more than that of short-term severe rain. For the dynamics, the Wsr0-6 index and SRH of hail are 15.5% and 34.7% more than that of short-term severe rain, respectively, and 24.5% and 55.5% more than that of thunderstorm, respectively, the EHI values of thunderstorm and hail are 40.9% and 138.0% more than that of short-term severe rain, respectively, and the Z0 and Z-20 of hail are 4.3% and 6.4% less than those of short-term severe rain, respectively.