暴雨过程中逆风区特征及应用判据研究          下载免费PDF全文

赵海军  李柏  潘玲  吴志彦  王庆华 《山东气象》2019,39(2):126-133

为研究暴雨过程中逆风区特征及应用判据,统计分析2010—2017年山东临沂地区暴雨过程中的多普勒雷达观测资料,结果表明：暴雨过程中,风暴内的垂直环流是造成逆风区发生发展的直接原因;逆风区表现为β中尺度和γ中尺度,其形态在不同天气类型下有明显差异;逆风区持续阶段降水强度增大,持续时间与过程累积雨量呈正相关;当雷达最低仰角识别到逆风区,其厚度≥4.0 km、强度≥15 m·s-1、径向速度绝对值最大值≥5 m·s-1且持续30 min以上时,风暴常明显发展,相关特征可用于预报风暴和暴雨的发展。  相似文献   

我国中东部平原地区临界气温条件下降水相态判别分析   总被引：1，自引：0，他引：1  

陈双  谌芸  何立富  郭云谦 《气象》2019,45(8):1037-1051

基于2001—2013年地面观测和探空资料,对地面气温位于0～2℃(以下称临界气温)我国降雪的时空分布及其与降雨的垂直热力特征进行了研究,引入了决策树判别方法对上述条件下雪和雨进行了判别分析,结果表明:临界气温下降雪出现频率总体高于降雨、雨夹雪出现频率,且在我国华北南部至江南北部的中东部地区分布较多,年均可达7.69～15.38站次;临界气温下,降水相态为雨或雪对应的平均温度廓线最大差异位于650 hPa附近,且地面气温较低时,平均温度差异更明显,平均湿度廓线差异则主要位于低层,且在地面气温较高时,平均湿度差异更明显;临界气温下,降水相态为雨时,地面上空存在暖层样本占比,较降水相态为雪时更高,且降雨时暖层主要位于中层,降雪时暖层则主要位于低层,降雨时其暖层强度显著大于降雪时暖层强度;在临界气温下雨雪判别分析中,地面气温能显著提升判别准确率,湿球温度能在一定程度上提升判别准确率,基于云顶温度、中层融化参数、低层湿球温度构建的决策树判别模型,判别准确率达到91.86%,能较好地解决临界气温下雨和雪的判别问题。  相似文献   

基于Himawari-8卫星的云参数和降水关系研究   总被引：1，自引：1，他引：0  

桂海林  诸葛小勇  韦晓澄  刘伯骏  唐志军  江琪 《气象》2019,45(11):1579-1588

基于日本Himawari-8卫星的云产品,对中国中东部地区2017年夏季(6—8月)每日08—17时的降水资料进行了分析,重点讨论了云光学厚度(COD)、云顶粒子平均尺度(CPS)、云顶温度(CTT)三个云参数与降水的关系。试验表明,降水概率与云参数相关性较高,存在随着COD增加、CPS增加、CTT减小而增加的明显趋势。但是,单个云参数与降水强度相关性则较低;COD、CPS、CTT与小时降雨率的相关系数分别为0.2315、0.1823、-0.2235,均为弱相关。如果综合考虑联合两个或三个云参数形成小时降雨率分布矩阵,则降水过程能得到更为清晰的体现。2017年8月28日的个例表明,相比纯粹基于红外的算法,三参数方法可以明显提高小时降雨率的估计精度。  相似文献   

2010—2016年江西省暖季短时强降水特征分析   总被引：2，自引：0，他引：2  

付超  谌芸  朱克云  单九生  曾智琳 《气象》2019,45(9):1238-1247

利用江西省2010—2016年5—9月1597个观测站逐小时降水资料对江西省短时强降水进行统计分析。采用REOF将降水场划分为5个区域：赣北南部（Ⅰ区）,抚州市及赣州中部（Ⅱ区）,赣北北部（Ⅲ区）,赣南南部、北部（Ⅳ区）以及赣中西部（Ⅴ区）。短时强降水高频区主要分布在山地及河谷附近,分别为湘赣交界罗霄山脉东侧、武夷山西侧、信江河谷、乐安河谷和昌江河谷。河谷附近短时强降水频次以昌江河谷最高（16.9次/a）,山地附近最高在罗霄山脉东侧（12.6次/a）,极端短时强降水分别位于上饶市东北部山区（3.7次/a）及九岭山南侧的锦江河谷（3.3次/a）。短时强降水主要发生在5月第3候,6、7月第3~4候以及8月第2~3候。Ⅳ、Ⅴ区具有单峰型的日变化特征;Ⅰ、Ⅱ、Ⅲ区具有双峰型的日变化特征。主峰基本集中在下午17时;次峰在上午08—10时。短时强降水对暴雨贡献率基本在40%以上,Ⅰ、Ⅱ区的暴雨天气过程将近一半是由短时强降水贡献的。信江河谷是暴雨雨量中心,但并不是短时强降水雨量中心;昌江河谷与武夷山西麓既是暴雨中心也是短时强降水中心。  相似文献   

Investigation into the daily precipitation variability in the Yangtze River Delta,China     

Yan‐Fang Sang  Zhonggen Wang  Zongli Li  Changming Liu  Xiaojie Liu 《水文研究》2013,27(2):175-185

In this article, by using the daily precipitation data measured at 58 meteorological stations, spatial and temporal variability of daily precipitation including zero rainfall values (called “precipitation”) and without zero rainfall values (called “rain”) and four precipitation extrema (P₀, P₂₀, P₅₀, and P₁₀₀ representing the daily precipitation with the magnitude smaller than 0.1 mm, bigger than 20 mm, 50 mm, and 100 mm per day, respectively) in the Yangtze River Delta (YRD) during 1958–2007 were analyzed, and the effects of urbanization were further investigated. Results indicate that (i) differing from the downward trends in 1958–1985, daily precipitation and rain in 1986–2007 show slowly downward trends in the mid YRD but show upward trends in the northern and southern YRD. (ii) Spatial and temporal variability of the rain is more complex than daily precipitation. Both of them become smaller but show more obvious fluctuations in 1986–2007. (iii) Urbanizations cause not only the urban rainfall island problem but also more obvious fluctuations of rain intensity in the mid YRD, reflecting more uncertainty of daily precipitation variability. (iv) Urbanizations have little effects on the variability of P₀ and P₁₀₀ but cause notable increases of P₂₀ and P₅₀. (v) The spatial variability of daily precipitation and precipitation extrema in 1958–1985 clearly shows a breakpoint at 30°20′N latitude, but the breakpoint disappears afterward because of the effects of urbanization. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

Application of FY-2C Cloud Drift Winds in a Mesoscale Numerical Model     

LI Huahong  WANG Man  XUE Jishan  QI Minghui 《Acta Meteorologica Sinica》2010,24(6):740-748

Statistical tests and error analysis of cloud drift winds(CDWs) from the FY-2C satellite were made by using radiosonde observations.According to the error characteristics of the CDW,a bias correction using the thermal wind theory was applied in the data quality control.The CDW data were then assimilated into the GRAPES-meso model via the GRAPES-3DVar.A torrential rain event that occurred in northwestern China during 1-2 July 2005 was simulated.The results indicate that the CDW data were mainly distribute...  相似文献   

Wet deposition of excess sulfate at Macquarie Island, 54° S     

G. P. Ayers  S. L. Ramsdale 《Journal of Atmospheric Chemistry》1988,7(4):317-323

Annual wet deposition of excess sulfate at Macquarie Island has been estimated from 5 months of rainwater composition data covering the Austral summer of 1985/86. The resulting figure of 2.1±0.6 mmol/m²/yr is at the low end of previous estimates of maritime excess sulfate deposition by precipitation. Within estimated uncertainty limits this figure is consistent with the DMS emission flux which would be predicted for latitude 50°–60° S, based solely on available Northern Hemispheric DMS measurements.Temporarily at the International Meteorological Institute, Stockholm University, S-106 91, Stockholm, Sweden.  相似文献   

四川省宁南县城后山泥石流激发雨强     

李德基  张德华 《山地学报》1994,(1)

根据宁南县城后山垂直剖面观测资料，对本区降雨的垂直变化及泥石流激发雨强作了探讨。当地暴雨泥石流发生所需的１０分钟雨强ｉ＿（１０ｍｉｎ）和前期降水量Ｐａ组合为：：ｉ＿（１０ｍｉｎ）≥１５ｍｍ∩Ｐａ≥５０ｍｍ，或ｉ＿（ｍｉｎ）≥１０ｍｍ∩Ｐａ≥６５ｍｍ，或ｉ＿（１０ｍｉｎ）≥５ｍｍ∩Ｐａ≥９０ｍｍ。超过上述各组合值就有可能暴发泥石流。  相似文献   

Formic and acetic acids in atmospheric condensate in Wilmington,North Carolina     

Joan D. Willey  Carol A. Wilson 《Journal of Atmospheric Chemistry》1993,16(2):123-133

Formic and acetic acids occurred in atmospheric condensate with concentrations similar to rainwater collected in Wilmington, North Carolina, during the sampling period from June to October of 1990. Atmospheric concentrations of these acids (calculated from the condensate concentrations) were higher in continental versus maritime air masses. Concentrations of formic and acetic acids were correlated with each other in both condensate and air. Traffic was a source of acetic acid and of bisulfite to atmospheric condensate in this study.  相似文献   

云、雨水酸度和离子浓度与其微物理参数的关系   总被引：3，自引：0，他引：3       下载免费PDF全文

刘奇俊  丁国安  汤洁  房秀梅  吴凡  苏维瀚 《气象学报》1993,51(2):195-202

本文1987年5-6月和1989年5-6月庐山地区的实测资料,分析了云、雨水酸度和离子浓度与其微物理量间的关系。结果表明,云、雨滴大小、含水量、谱宽等微物理量的演变直接影响着其酸度和离子浓度。  相似文献