摘要
利用风廓线雷达资料、探空和自动站逐小时降水资料，对2009-2014年南沙区42次有低空急流相伴出现的短时强降水环流配置及垂直结构中尺度特征进行分析，建立3种短时强降水模型，探讨了3类短时强降水与低空急流上中小尺度系统的关系以及降水强度与低空急流指数的关系。结果表明：急流轴上中小尺度系统的时间尺度在0．5—4h，其对强降水出现有极强的预示作用，其中低空急流中尺度风速脉动出现比强降水提前0．5～6h，急流轴下传出现比强降水提前3～6h。急流指数增幅与雨强存在正比关系，强降水发生前1～2h内低空急流指数增幅大小，也是短时强降水临近预警的一个重要指标。
With the data from a wind profiler, radiosondes and automatic weather stations （hourly precipitation）, we studied the circulation allocation and mesoscale characteristics of the vertical structure of 42 processes of short-range intensive rain accompanied with low-level jet streams in the Nansha District, Guang- zhou from 2009 to 2014. Three models of short-range intensive rain were set up and the relationships between them and meso- and short-scale systems in low-level jet streams （LLJS） and between rain intensity and LLJS indexes were discussed. The result is shown as follows. The time scale is from 0.5 to 4 h for the meso- and short-scale systems, well indicative of the occurrence of intensive rain. Of the indicators, mesoseale wind speed fluctuation of the LLJS appears 0.5 to 6 h ahead of the intensive rain while the downward transport of LLJS axis occurs 3 to 6 h prior to it. The amplitude of LLJS growth is proportional to rain rates. The amplitude of the LLJS index increase 1 to 2 h before the intensive rain, which is also an important indicator in the nowcasting of short-range intensive rain.
作者
祁秀香
李海洋
赵小伟
林中庆
王开燕
Q LI Hai-yang ZHAO Xiao-wei LIN Zhong-qing WANG Kai-yan(Meteorological Bureau of Nansha District, Guangzhou, Guangzhou 511462)
出处
《广东气象》
2016年第5期20-24,共5页
Guangdong Meteorology
基金
中国气象局关键技术项目(CMAGJ2014M39)
广东气象局创新团队(201102)
行业专项(GYHY201406009)共同资助
关键词
天气学
低空急流
短时强降水
风廓线雷达
临近预警
广州南沙区
synoptics
low-level jet stream
short-range intensive rain
wind profiler
nowcasting
Nansha District, Guangzhou
