宁夏40年灾害性冰雹天气分析

Analysis of disastrous hail weather in Ningxia in recent 40 years

利用1961-2000年5-9月常规地面观测资料及相应时段的NCEP/NCAR逐日全球再分析资料,分析了宁夏灾害性冰雹天气的时空分布和环流特征,然后对74次有灾情记录的冰雹天气过程的环流背景、影响系统等进行了合成对比分析。结果表明:宁夏冰雹主要分布在南部六盘山区和北部贺兰山区,集中出现在6-7月;冰雹发生于"西高东低"环流背景下;产生冰雹天气主要有平直气流、两槽一脊、一槽一脊和一脊一槽等4种环流形势;影响系统主要有切变线、低涡和冷槽,这几种系统往往是共同作用、共同影响的;同时也表明,在不同的环流背景下,不同影响系统造成的冰雹天气落区有较大的差异。

Using the normal ground observation data and global reanalyzed daily data of NCEP/NCAR for the corresponding time, from May to September between 1961 -2000, firstly we analyzed the character of circulation and Spatial and temporal distribution of hail weather in Ningxia. Then through contrast, we analyzed the circulation background and influencing system of 74 times hail weather that had disaster records. The result shows that the hail of Ningxia had two mainly distributed area near the southern Liupan Mountain area and the northern Helan Mountain area and mainly appears in June to July. To hail＇s occurrence , the favorable circulation background was high-pressure in the west and low-pressure in the east of Ningxia and there are four primary circulation situations straight air current , two troughs and one ridge, one trough and one Three mainly influencing systems of hail weather included shear line, vortex and ridge, one ridge and one trough. cold trough. All these influencing systems often act and influence each other. The result also shows that under the different circulation background, different affecting system could cause hail weather that has obvious difference in distributed area.