2008—2013年通辽地区冰雹天气时空特征分析

Analysis on Spatial and Temporal Characteristics of Hail in Tongliao Area from 2008 to 2013

通过对2008—2013年通辽地区的冰雹天气过程进行时空特征统计分析,以期为今后冰雹出现的时空分布提供有力的判断依据,提高冰雹的预报预警能力。结果表明,通辽地区的冰雹天气主要分布于北部和南部山区,平原地区相对偏少,这和通辽市北部为大兴安岭南麓余脉的石质山地丘陵,南部为辽西山地边缘的浅山、黄土丘陵区,中部为西辽河流域沙质冲积平原的地形(通辽市地势南部和北部高,中部低平,呈马鞍形)分布特点是密不可分的。发生冰雹最多的是6月,7月次之。冰雹发生的高峰期(6月)在降雨高峰期(7月、8月)之前,这同冰雹的形成特性和副热带高压的季节性进退有密切关系。通辽地区降雹高度集中在午后至傍晚,说明在午后至傍晚气温日变化最大的时段里,湍流作用致使大气层结不稳定更易造成强对流天气。

The spatial and temporal characteristics of hail in Tongliao area from 2008 to 2013 were analyzed in order to provide a strong judgment and improve the forecast ability for hail. The results showed that the hail weather mainly happened in the northern and southern mountainous area, and rarely happened in plain region. The spatial distribution of hail in Tongliao area was closely related to the saddle shaped terrain which high in the north and south ,and low in middle area. The hail mainly occurred in June ,and ahead of its peak rainfall season（July and August）. This was closely related to the formation of hailstones and the seasonal subtropical high. The hail mainly happened in the afternoon and evening and it illustrated that the instability of atmosphere caused by turbulenee may let to the strong convection weather.