珠江三角洲地区两次夏季典型雷电天气系统的雨滴谱特征观测研究  

Observation Studies on Characteristics of Raindrop Size Distribution of Two Typical Summer Thunderstorm Cases in the Pearl River Delta

作　　者：廖菲[1,2] 邓华[1,2] 万齐林[1,2] 钱嘉星 黄辉军[1,2] 毛伟康[1,2] 

机构地区：[1]中国气象局广州热带海洋气象研究所,广东广州510080 [2]中国气象局热带季风重点开放实验室,广东广州510080 [3]广州市气象台,广东广州510080

出　　处：《高原气象》2011年第3期798-808,共11页Plateau Meteorology

基　　金：公益性行业(气象)科研专项(GYHY200706014);广东省社会发展气象领域科技计划项目"海陆差异对登陆台风暴雨影响的观测与数值研究";广东省自然科学基金项目"广东省登陆台风暴雨的边界层特征研究";公益性科研院所基本科研费项目"海洋气象灾害的观测-模式试验及应用平台的建设"共同资助

摘　　要：为了进一步研究珠江三角洲地区夏季典型雷电天气系统影响下降水微物理特征,选取2008年6月13日锋面过程和6月25日台风登陆过程所引起的两次降水过程为研究对象,利用Parsivel激光降水粒子谱测量系统获取的雨滴尺度谱和速度谱的观测信息,对这两次降水的雨滴谱特征进行了较深入的分析。结果表明,锋面和台风影响下的两次降水过程中雨滴平均立方根直径的大小基本相当,分别为1.14mm和1.18mm;台风降水的平均雨滴数密度为1 082个.m-3,而锋面降水的平均雨滴数密度为717个.m-3,但锋面降水的最大瞬时雨强较大。两次降水过程中,除雨水含量与雨强有较好的相关外,其他各谱特征量与雨强的相关表现不一。云系不同部位雨滴谱各谱特征量有所不同,对流性降水区雨滴直径相对较大,雨滴数密度也较大,含水量的贡献主要来自大雨滴。锋面降水中雨滴的分布具有典型的非均匀性,各粒径档内雨滴数浓度的起伏变化剧烈,尤以较大直径的雨滴数浓度在不同降水阶段时变化最为明显,降水过程雨滴谱的谱宽一直较大,且在降水旺盛时期表现出双峰(多峰)的谱型分布;台风降水中除较小粒径内雨滴数浓度变化较大外,同一时刻其他各粒径档内雨滴数浓度基本相当,雨滴谱是典型的单峰型分布。Two typical summer thunderstorm cases initiated by cold front and typhoon weather systems,which happened on 13 and 25 June 2008,respectively,are selected to study thunderstorm precipitation microphysics in the Pearl River Delta of South China.Data of raindrop size distribution（RSD） and drop velocity spectrum observed by Parsivel present weather sensor are used to research characteristics of thunderstorm RSD.The results show that the average cube root diameters of raindrops of the two cases are 1.14 mm and 1.18 mm,respectively,that are quite equal.Average number concentration of raindrop of typhoon precipitation is 1 082 m-3,and that in cold front precipitation is just 717 m-3,but the maximum instantaneous precipitation intensity of cold front is relative bigger.Correlation coefficient of rainwater content and precipitation intensity is quite high,while other physical features of RSD do not correlative well to precipitation intensity.Physical feature of RSD vary with the position of the observation station relative to the cloud cluster,and diameter and number concentration of raindrops are comparatively larger in convective precipitation than in stratiform precipitation,which means rainwater content is mostly contributed by larger size raindrops.The types of RSD exhibit inhomogeneous feature,and number concentration of different size raindrops,especially relative bigger size raindrops,vary in wide range.Spectrum width of RSD continuously keeps comparatively larger in the cold front,and the spectrum type is bimodal or multimodal distribution in mature period of precipitation process.While in the typhoon precipitation,number concentration of relative small size raindrops vary obviously,and spectrum type of RSD keeps unimodal distribution during whole precipitation process.

关 键 词：珠江三角洲地区 雨滴谱 雷电天气系统 

分 类 号：P458[天文地球—大气科学及气象学]