摘要
利用常规观测资料、NCEP 1°×1°的6h再分析资料和地面加密自动气象观测资料,分析了2010年5月15日发生在新疆沙雅县境内的一次强冰雹天气。分析显示,巴尔喀什湖低槽、冰雹区上游的中尺度切变线是冰雹天气的直接影响系统,其水汽源于塔里木盆地西部和中部地区,水汽在低层集中和输送,冰雹区上空的辐合上升运动为冰雹出现提供了水汽和动力条件,强冰雹产生在地面高能区附近,冰雹发生前低层和整层大气存在不稳定能量。此次强冰雹过程中对应地面上有中尺度低压、中尺度辐合线和中尺度涡旋,强冰雹是由γ中尺度对流单体产生的,中尺度辐合线维持5h,中尺度涡旋维持3h,γ中尺度对流单体的生命史为30min左右。
Using the conventional observation data, NCEP （1°× 1° lat/lon, 6 hours） reanalysis data and surface intensive automatic meteorological observation data, a severe hail event occurred on 15 May 2010 in Shaya County, Xingjiang is analyzed. The results show that the major influencing systems of the hail event include the low trough over Lake Balkhash and the mesoscale shear line upstream of the hail region, whose vapor came from the west and middle regions of the Tarim basin, gathered and dispersed at the lower levels of the atmosphere. The convergent ascending motion over the hail region provided the vapor and dynamic conditions for the hail. The severe hail event appeared near the high energy region at surface. There existed unstable energies both at the lower levels and in the whole atmosphere before the hail. During the course of the severe hail, there was a mesoscale low pressure, a mesoscale convergence line, and a mesoscale vortex at surface. The severe hail was produced by a T mesoscale convective cell. The mesoscale convergence line and mesoscale vortex lasted for 5 hours and 3 hours, respectively, and the lifetime of the T mesoscale convective cell was about 30 minutes.
出处
《气象科技》
2012年第3期436-444,共9页
Meteorological Science and Technology
基金
中国沙漠气象科学研究基金项目(sqj2010004)
科技部公益性行业科研专项(GYHY201006012)资助
关键词
强冰雹
中尺度切变线
湿静力温度
severe hail, mesoscale shear line, wet static temperature
