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投稿时间:2016-04-05 修订日期:2016-11-25
投稿时间:2016-04-05 修订日期:2016-11-25
中文摘要: 应用黄山地区191个地面自动观测站资料,统计分析了2015年发生在黄山地区短时强降雨时空分布。统计发现:发生短时强降雨过程次数在午后及傍晚(14和18时)时段中明显增多;黄山山脉及其附近是短时强降雨多发生的中心地带,发生短时强降雨次数分布与山脉形态一致、和地形高度相关,短时强降雨与地形关系密切。分别利用三个典型个例分析了山脉地形动力阻拦和热力对短时强降雨的增幅作用,结果表明:(1)山脉地形迎风坡处因地形抬升速度与地面辐合线相配合降雨增强,水汽收支方法诊断计算降雨增量可达6成;(2)锋面过境山脉时垂直扰动增强水平位温梯度增大锋生,在背风坡处地面涡度、上升运动增强,导致降水增幅;(3)山脉西南区域因地面感热通量差异形成热低压,在该区域增暖增湿,大气不稳定增强,受冷平流影响形成强对流天气,导致山区降水增幅。
中文关键词: 黄山山脉,短时强降雨,地形抬升,锋生,热低压
Abstract:The spatio temporal distribution of short time heavy rainfall in Huangshan Mountain region was analyzed statistically by using the observations from 191 ground automatic observation stations in Huang shan Mountain region. Statistics revealed that the frequency of short time severe rainfall process increases significantly from afternoon to evening (14:00-18:00) period; short time severe rainfall occurs most often in Huangshan Mountain and the nearby area; the distribution of short term heavy rainfall frequency is highly correlated with mountain shape and terrain. Using three typical cases, the function of the enhancement of mountain terrain dynamic blocking and thermodynamics in short time severe rainfall is analyzed. The findings are concluded as follows: (1) The rainfall increases due to the lifting rate of mountain terrain on the windward slope, and the rainfall coulds reach 60% according to the diagnosis by the water vapor budget method. (2) When the frontal surface passes the mountain area, its vertical disturbance enhances frontogenesis, while in the leeward slope, the surface vortex, and ascending motion are enhanced, result ing in the increase in precipitation. (3) In the southwest region thermal low forms due to the difference of surface latent heat flux, making this area warmer and wetter and the atmospheric instability enhanced. Affected by cold advection, severe convective weather develops, thus increasing the precipitation in the mountain region.
keywords: Huangshan Mountain, short time severe rainfall, topographic uplift, frontogenesis, thermal low
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基金项目:安徽省自然科学基金项目(1508085MD64)、中国气象局(CMAGJ2015M28)和公益性行业(气象)科研专项(GYHY201306040)共同资助
作者 | 单位 |
刘裕禄 | 安徽省黄山市气象台,黄山 245021 安徽省大气科学与卫星遥感重点实验室,合肥 230031 |
杜其成 | 安徽省黄山市气象台,黄山 245021 |
黄勇 | 安徽省大气科学与卫星遥感重点实验室,合肥 230031 安徽省气象研究所,合肥 230031 |
引用文本:
刘裕禄,杜其成,黄勇,2017.黄山地区短时强降雨的地形增幅机制[J].气象,43(2):181-188.
LIU Yulu,DU Qicheng,HUANG Yong,2017.The Topograpical Enhancement Mechanism of Short Time Heavy Rainfall in Huangshan Mountain[J].Meteor Mon,43(2):181-188.
刘裕禄,杜其成,黄勇,2017.黄山地区短时强降雨的地形增幅机制[J].气象,43(2):181-188.
LIU Yulu,DU Qicheng,HUANG Yong,2017.The Topograpical Enhancement Mechanism of Short Time Heavy Rainfall in Huangshan Mountain[J].Meteor Mon,43(2):181-188.