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江西短时强降水极端阈值与回波特征分析
Analysis of extreme threshold and echo characteristics of short-term heavy precipitation in Jiangxi Province
【摘要】 为了更好地研究短时强降水的极端性。文章使用2012—2021年江西短时强降水(≥30 mm/h)出现频次、量级等数据,采用百分位算法,对江西短时强降水极端阈值进行分析。结果表明:江西短时强降水极端阈值国家站为≥80 mm/h±2%,区域站为≥90 mm/h±2%;江西极端短时强降水的雷达回波特征为存在多条不同走向回波短带的絮状回波带结构,组合反射率为50~55 dBZ(超强时可达60 dBZ),≥45 dBZ的强回波面积≥300 km~2,强回波移动缓慢或少动使得强降水维持,出现“超短时强降水”(≥10 mm/10 min),55 dBZ椭圆形强回波移动缓慢也是造成极端强降水的回波系统。研究结果确定了短时强降水极端阈值,为开展江西极端强降水提供了分析依据。
【Abstract】 In order to better study the extreme nature of short-term heavy precipitation.The article uses data on the frequency and magnitude of short-term heavy precipitation(≥30 mm/h) in Jiangxi from 2012 to 2021,and uses the percentile algorithm to analyze the extreme threshold of short-term heavy precipitation in Jiangxi.The results showed that the extreme threshold for short-term heavy precipitation in Jiangxi is ≥80 mm/h ±2% for national stations and ≥90 mm/h ±2% for regional stations.The radar echo characteristics of extreme short-term heavy precipitation in Jiangxi Province are characterized by the presence of multiple flocculent echo bands with different directions, with a combined reflectivity of 50 dBZ to 55 dBZ(up to 60 dBZ in super strong cases).The area of strong echoes with a reflectivity of ≥45 dBZ is ≥300 km~2,and the slow or minimal movement of strong echoes maintains the heavy precipitation, resulting "ultra short time heavy precipitation"(≥10 mm/10 min).The slow movement of elliptical strong echoes with a reflectivity of 55 dBZ is also the echo system that causes extreme heavy precipitation.The research results have determined the extreme threshold for short-term heavy precipitation, providing an analytical basis for carrying out extreme heavy precipitation in Jiangxi.
- 【文献出处】 气象水文海洋仪器 ,Meteorological,Hydrological and Marine Instruments , 编辑部邮箱 ,2024年06期
- 【分类号】P426.6
- 【下载频次】81