首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献，搜索用时 43 毫秒
1.
山西云微物理特征的地面观测   总被引：3，自引：1，他引：2  
利用连续气流纵向热梯度云凝结核仪和激光降水粒子谱测量仪对山西地面的云凝结核和雨滴谱进行了观测研究.研究结果表明,云凝结核(CCN)数浓度具有明显的日变化特征,1天出现了两次峰值,数浓度日变化与气象因子、人类活动有关.降水对CCN具有冲刷作用.利用关系式NCCN=CSk拟合得到的地面CCN活化谱参数C值明显较大,k值较高,属于典型的大陆型核谱.对层状云、层积云降水雨滴微物理特征参量分析发现:3次层状云、层积云降水雨滴数密度变化范围分别为74～229 m-3、305～743 m-3,平均含水量量级分别为10-2 g/m3、10-1g/m3,最大雨滴直径分别为1.78 mm、4.7 mm.对层状云降水雨滴的数密度和雨强贡献较大的分别是小于1 mm、0.2～2 mm的雨滴;对层积云降水雨滴的数密度和雨强贡献较大的分别是0.2～2 mm、1～3 mm的雨滴.层积云出现稳定谱的比例高于层状云.从瞬时谱型分布看,层状云出现单、双、三峰多,第四、五峰值的频率比较少,层积云雨滴谱分布没有出现指数型,常有多峰.从平均谱分布看,层状云谱宽窄于层积云,层状云雨滴平均谱服从指数分布,层积云曲线呈向下弯曲的趋势.对汾阳2008年7月17日一次积层混合云降水雨滴谱资料分析发现积层混合云降水雨滴微物理量起伏大,降水雨强主要由雨滴数密度决定.相同雨强下,若有相对更多的大雨滴,雷达反射率会更大一些.随着强回波云块的过境,雨滴数浓度、雨滴谱峰值个数、谱宽均明显增大.  相似文献   

2.
为研究梅雨期极端对流系统的微物理特征,利用2013—2014年江淮梅雨期间南京溧水S波段双偏振雷达探测资料和地面自动站小时降水资料,统计分析了两类极端对流降水系统的微物理特征及差异。这两类极端对流系统的定义基于地面降水强度和雷达回波顶高,分别为所有对流中降水强度最强的1%（R类:小时降水强度>46.2 mm/h）和对流发展高度最高的1%（H类:20 dBz回波顶高>14.5 km）。结果显示这两类极端对流系统仅有30%的样本重合,显示了二者之间的弱相关性。对于相同的反射率因子ZH,R类极端对流系统的近地面差分反射率因子ZDR通常较H类极端对流小约0.2 dB,表明R类极端对流具有较小的平均粒径。结合双偏振雷达反演的粒子大小和相态分布显示,虽然两类极端对流都表现出海洋性对流降水特征,但R类极端对流较H类极端对流的总体雨滴粒径更小而数浓度更高,导致R类极端对流系统的地面降水更强。与R类极端对流系统相比,H类极端对流系统的上升运动更强,将更多的水汽和过冷水输送到0℃层以上,有利于形成更大的冰相粒子（如霰粒子等）,并通过融化形成大雨滴。以上研究表明,梅雨期降水强度和对流发展深度并没有必然的联系,极端降水主要是中等高度的对流引起。   相似文献   

3.
雨滴谱的垂直变化特征对于认识降水过程、改进模式和雷达定量估计降水等具有重要意义。利用2016年6月1日-9月30日雨量筒、微雨雷达（micro rain radar,简称MRR）和PARSIVEL雨滴谱仪连续4个月的观测数据,在对比3种仪器观测结果的基础上,研究了层状云降水不同降水强度下微物理特征量和雨滴谱垂直演变特征。结果表明:MRR与PARSIVEL雨滴谱仪观测降水强度相关性较好,且两种仪器观测的雨滴谱在中等粒子段（0.5~2.5 mm）表现出较好的一致性,而对于小粒子段（雨滴直径小于0.5 mm）PARSIVEL雨滴谱仪观测的数浓度明显低于MRR。对于弱降水（降水强度R ≤ 0.2 mm·h-1）,液水含量和降水强度随高度降低减小,雨滴在下落过程中蒸发明显。对于较强降水（R>2 mm·h-1）,随高度降低,雷达反射率因子增大,小滴数浓度减小的同时大滴数浓度增加明显,雨滴下落过程碰并作用明显。所有高度直径不超过0.5 mm的小滴对数浓度贡献均为最大。高层雨滴直径不小于1 mm的小粒子对降水强度的贡献可达50%,小粒子对降水强度贡献随高度降低减小。  相似文献   

4.
High-resolution numerical simulation data of a rainstorm triggering debris flow in Sichuan Province of China simulated by the Weather Research and Forecasting (WRF) Model were used to study the dominant cloud microphysical processes of the torrential rainfall. The results showed that: (1) In the strong precipitation period, particle sizes of all hydrometeors increased, and mean-mass diameters of graupel increased the most significantly, as compared with those in the weak precipitation period; (2) The terminal velocity of raindrops was the strongest among all hydrometeors, followed by graupel’s, which was much smaller than that of raindrops. Differences between various hydrometeors’ terminal velocities in the strong precipitation period were larger than those in the weak precipitation period, which favored relative motion, collection interaction and transformation between the particles. Absolute terminal velocity values of raindrops and graupel were significantly greater than those of air upward velocity, and the stronger the precipitation was, the greater the differences between them were; (3) The orders of magnitudes of the various hydrometeors’ sources and sinks in the strong precipitation period were larger than those in the weak precipitation period, causing a difference in the intensity of precipitation. Water vapor, cloud water, raindrops, graupel and their exchange processes played a major role in the production of the torrential rainfall, and there were two main processes via which raindrops were generated: abundant water vapor condensed into cloud water and, on the one hand, accretion of cloud water by rain water formed rain water, while on the other hand, accretion of cloud water by graupel formed graupel, and then the melting of graupel formed rain water.  相似文献   

5.
The polarimetric radar network in Jiangsu Province has just been operationalized since 2020. The first intense precipitation event observed by this polarimetric radar network and disdrometer occurred during August 28-29, 2020 and caused severe flooding and serious damage in eastern Jiangsu Province. The microphysics and kinetics for this heavy precipitation convective storm is diagnosed in this study, in order to promote the application of this polarimetric radar network. Drop size distribution (DSD) of this event is estimated from measurements of a ground disdrometer, and the corresponding three-dimensional atmospheric microphysical features are obtained from the multiple polarimetric radars. According to features of updraft and lighting, the evolution of the convective storm is divided into four stages: developing, mature with lightning, mature without lightning and dissipating. The DSD of this event is featured by a large number of raindrops and a considerable number of large raindrops. The microphysical characteristics are similar to those of warm-rain process, and ice-phase microphysical processes are active in the mature stages. The composite vertical structure of the convective storm indicates that deep ZDR and KDP columns coincide with strong updrafts during both mature stages. The hierarchical microphysical structure retrieved by the Hydrometeor Identification Algorithm (HID) shows that depositional growth has occurred above the melting level, and aggregation is the most widespread ice-phase process at the -10℃ level or higher. During negative lightning activity, the presence of strongest updrafts and a large amount of ice-phase graupel by riming between the 0℃ and -35℃ layers generate strong negative electric fields within the cloud. These convective storms are typical warm clouds with very high precipitation efficiency, which cause high concentration of raindrops, especially the presence of large raindrops within a short period of time. The ice-phase microphysical processes above the melting layer also play an important role in the triggering and enhancing of precipitation.  相似文献   

6.
This paper investigates spatial and temporal distributions of the microphysical properties of precipitating stratiform clouds based on Doppler spectra of rain particles observed by an L-band profiler radar.The retrieval of raindrop size distributions（RSDs） is accomplished through eliminating vertical air motion and isolating the terminal fall velocity of raindrops in the observed Doppler velocity spectrum.The microphysical properties of raindrops in a broad stratiform region with weak convective cells are studied using data collected from a 1320-MHz wind profiler radar in Huayin,Shaanxi Province on 14 May 2009.RSDs and gamma function parameters are retrieved at altitudes between 700 and 3000 m above the surface,below a melting layer.It is found that the altitude of the maximum number of raindrops was closely related to the surface rain rate.The maximum number of large drops was observed at lower altitudes earlier in the precipitation event but at higher altitudes in later periods,suggesting decreases in the numbers of large and medium size raindrops.These decreases may have been caused by the breakup of larger drops and evaporation of smaller drops as they fell.The number of medium size drops decreased with increasing altitude.The relationship between reflectivity and liquid water content during this precipitation event was Z = 1.69×10~4M~（1.5）,and the relationship between reflectivity and rain intensity was Z = 256I~（1.4）.  相似文献   

7.
During the April-June raining season,warm-sector heavy rainfall(WR) and frontal heavy rainfall(FR) often occur in the south of China,causing natural disasters.In this study,the microphysical characteristics of WR and FR events from 2016 to 2022 are analyzed by using 2-dimensional video disdrometer(2DVD) data in the south of China.The microphysical characteristics of WR and FR events are quite different.Compared with FR events,WR events have higher concentration of D<5.3 mm(especially D <1 ...  相似文献   

8.
本文利用乌鲁木齐PARSIVAL激光雨滴谱仪2012-2013年观测资料，对春、夏、秋季不同雨强降雨的雨滴谱微物理特征参量及其随时间演变特征、Gamma函数拟合、 关系等进行研究。结果表明：（1）乌鲁木齐降雨以小粒子为主，大雨强降雨的6种特征直径最大，中雨强降雨次之，小雨强降雨最小。雨滴数密度主要来自于小雨滴（直径<1 mm），大雨滴（直径>3mm）是雨强的主要贡献者，中雨滴（直径1-3 mm）是含水量和雷达反射率因子的主要贡献者，雷达反射率因子受雨滴尺寸影响很大。（2）小雨强降雨各微物理参量比较稳定，变化幅度不大，大雨强降雨则变化剧烈，出现多峰型，中雨强降雨介于二者之间。大雨强降雨的谱宽和峰值浓度最大，小雨强降雨最小，中雨强降雨介于二者之间，小雨强降雨的拟合谱具有明显的季节差异性；秋季峰值浓度最大，这与秋季多大风天气有关。（3）Gamma拟合参数 关系与粒子尺寸有关，可以用二项式进行描述。拟合出的 关系系数均小于目前常用的 关系，因此，利用 关系在乌鲁木齐进行降雨定量估测研究时会造成对降雨强度的高估，回波强度越大，高估越明显。夏季大雨强降雨无法拟合出相关系数比较高的 关系，这与乌鲁木齐大雨强降雨具有强度大、时间短、随时间变化迅速的特点有关。  相似文献   

9.
雨滴谱包含了降雨的丰富信息,不仅能反映雨滴群的微物理特性,也能反映降雨类型、降雨强度等宏观特性,并且在雷达气象领域也有重要的价值。论文对2015和2016年度南京地区32次降雨过程的雨滴谱资料进行了处理、并对多种雨滴参数进行了详细的统计和分析,拟合了层状云降雨、对流云降雨以及积层混合云降雨的雨滴谱Gamma分布参数。另外,还基于雨滴谱数据拟合了雷达反射率因子Z与降雨强度R的Z-R关系,计算了差分反射率ZDR、相位常数KDP以及衰减参数,并利用衰减参数进行了C波段雷达回波的衰减订正试验。结果表明:（1）层状云降雨的各微物理参数比较稳定,积雨云的变化剧烈;层云降雨和积层混合云降雨的中雨滴、积雨云降雨的大雨滴对雷达反射率因子的贡献最大。（2）积雨云降雨的滴谱最宽,层状云降雨的最窄。（3）利用依据雨滴谱数据拟合的三类降雨Z-R关系,可以一定程度地提高雷达估测降雨的精度。（4）利用基于雨滴谱数据拟合的衰减系数,有效地进行了C波段双偏振雷达回波强度的衰减订正,体现了统计参数和拟合参数准确性。  相似文献   

10.
2015年10月29日弱降雨前后的层状云微物理参数反演和分析   总被引：4，自引：4，他引：0  
利用Ka波段毫米波云雷达和微波辐射计资料对2015年10月29日安徽寿县的一次弱降雨过程的云参数进行了反演,所采用的反演方案是单参数法和双参数法。论文先介绍了单参数和双参数反演方法,然后反演了降雨前后的云微物理参数,对比分析表明：（1）降水发生前云滴数浓度较大,典型值1 000个·cm-3左右,有效半径小于4.5 μm;（2）降雨后,云滴数浓度显著减小,典型值在500个·cm-3左右,但有效半径略增大了1~1.5 μm;（3）云中含水量的变化不明显,降雨后略增大,增加量在0.1 g·m-3以内; （4）降水发生前,云微物理参数随高度的起伏较大,降水后的廓线比较平缓,显示出降雨后的云层动力特性更稳定。  相似文献   

11.
To analyze the effects of gas cannons on clouds and precipitation, multisource observational data, including those from National Centers for Environmental Prediction (NCEP) reanalysis, Hangzhou and Huzhou new-generation weather radars, laser disdrometer, ground-based automatic weather station, wind profiler radar, and Lin''an C-band dual polarization radar, were adopted in this study. Based on the variational dual-Doppler wind retrieval method and the polarimetric variables obtained by the dual-polarization radar, we analyzed the microphysical processes and the variations in the macro - and microphysical quantities in clouds from the perspective of the synoptic background before precipitation enhancement, the polarization echo characteristics before, during and after enhancement, and the evolution of the fine three-dimensional kinematic structure and the microphysical structure. The results show that the precipitation enhancement operation promoted the development of radar echoes and prolonged their duration, and both the horizontal and vertical wind speeds increased. The dual-polarization radar echo showed that the diameter of the precipitation particles increased, and the concentration of raindrops increased after precipitation enhancement. The raindrops were lifted to a height corresponding to 0 to -20 ℃ due to vertical updrafts. Based on the disdrometer data during precipitation enhancement, the concentration of small raindrops (lgNw) showed a significant increase, and the mass-weighted diameter Dm value decreased, indicating that the precipitation enhancement operation played a certain“lubricating”effect. After the precipitation enhancement, the concentration of raindrops did not change much compared with that during the enhancement process, while the Dm increased, corresponding to an increase in rain intensity. The results suggest the positive effect of gas cannons on precipitation enhancement.  相似文献   

12.
The water vapor budget and the cloud microphysical processes associated with a heavy rainfall system in the Dabie Mountain area in June 2008 were analyzed using mesoscale reanalysis data(grid resolution 0.03 × 0.03,22 vertical layers,1-h intervals),generated by amalgamating the local analysis and prediction system(LAPS).The contribution of each term in the water vapor budget formula to precipitation was evaluated.The characteristics of water vapor budget and water substances in various phase states were evaluated and their differences in heavy and weak rainfall areas were compared.The precipitation calculated from the total water vapor budget accounted for 77% of actual precipitation;surface evaporation is another important source of water vapor.Water vapor within the domain of interest mainly came from the lower level along the southern boundary and the lower-middle level along the western boundary.This altitude difference for water vapor flux was caused by different weather systems.The decrease of local water vapor in the middle-lower layer in the troposphere during the system development stage also contributed to precipitation.The strength and the layer thickness of water vapor convergence and the content of various water substances in the heavy rainfall areas were obviously larger than in the weak rainfall areas.The peak values of lower-level water vapor convergence,local water vapor income,and the concentration of cloud ice all preceded the heaviest surface rainfall by a few hours.  相似文献   

13.
Warm-sector heavy rainfall (WR), shear-line heavy rainfall (SR), and frontal heavy rainfall (FR) are three types of rainfall that frequently occur during the pre-summer rainy season in south China. In this research, we investigated the differences in microphysical characteristics of heavy rainfall events during the period of 10-15 May 2022 based on the combined observations from 11 S-band polarimetric radars in south China. The conclusions are as follows: (1) WR has the highest radar echo top height, the strongest radar echo at all altitudes, the highest lightning density, and the most active ice-phase process, which suggests that the convection is the most vigorous in the WR, moderate in the FR, and the weakest in the SR. (2) Three types of rainfall are all marine-type precipitation, the massweighted mean diameter (Dm, mm) and the intercept parameter (Nw, mm-1 m-3 ) of the raindrops in the WR are the largest. (3) The WR possesses the highest proportion of graupel compared with the FR and SR, and stronger updrafts and more abundant water vapor supply may lead to larger raindrops during the melting and collision-coalescence processes. (4) Over all the heights, liquid and ice water content in the WR are higher than those in the SR and FR, the ratio of ice to liquid water content in the WR is as high as 27% when ZH exceeds 50 dBZ, definitely higher than that in the SR and FR, indicating that the active ice-phase process existing in the WR is conducive to the formation of heavy rainfall.  相似文献   

14.
黄山不同高度雨滴谱的演变特征   总被引：1，自引：0，他引：1       下载免费PDF全文
选取2011年6月黄山地区一次降水过程,利用测得的雨滴谱资料对不同高度上降水微物理量及雨滴谱分布特征进行分析,并讨论其中的差异。结果表明:此次降水较强,各直径微物理量在山腰最大、山底次之、山顶最小;山腰的雨强最大,而山顶数浓度最大。在雨滴谱分布中,小于1mm的雨滴数密度是山顶大于山腰大于山底,这与小雨滴的蒸发和碰并有关;大于1.5 mm的雨滴数密度则是山腰大于山顶和山底,这可能与地形抬升使得云系加强有关。由各微物理量的时间序列可将降水过程分为两个阶段,第一阶段各微物理量值明显大于第二阶段,其中第一阶段的降水量约为第二阶段的3倍。雨强与雷达反射率、数浓度、最大直径近似成幂函数关系,其中雨强与雷达反射率相关性最好。  相似文献   

15.
研究不同云系降水的微物理参数特征,对研究降水机制、人工影响天气、雷达定量测量降水、数值预报模式中微物理参数化方案的选择等都有一定意义。本文针对2015年济南地区的液态降水过程,基于微降水雷达(Micro Rain Radar,简称MRR)资料,研究不同云系降水的微物理参数。在400 m高度上,层状云降水0.02~0.2 mm h-1雨强样本数很大,但对累计降水量的贡献很小。混合云和对流云降水在大粒子端数浓度较高。在垂直方向上,层状云降水中的粒子的尺度较集中,中值体积直径D0平均在1 mm左右,随高度的变化不大。对流云降水在雨强大于20 mm h-1时,强垂直气流(包括上升气流和下沉气流)对粒子直径的影响较大,进而影响空中微降水雷达反演降水参数的数据质量。而垂直气流的影响对层状云降水影响较小,在层状云降水时,微降水雷达可以用来分析零度层亮带以下雨滴谱在垂直方向上的演变。  相似文献   

16.
By using the cloud echoes first successfully observed by China's indigenous 94-GHz SKY cloud radar, the macrostructure and microphysical properties of drizzling stratocumulus clouds in Anhui Province on 8 June2013 are analyzed, and the detection capability of this cloud radar is discussed. The results are as follows.(1) The cloud radar is able to observe the time-varying macroscopic and microphysical parameters of clouds,and it can reveal the microscopic structure and small-scale changes of clouds.(2) The velocity spectral width of cloud droplets is small, but the spectral width of the cloud containing both cloud droplets and drizzle is large. When the spectral width is more than 0.4 m s-1, the radar reflectivity factor is larger(over –10 dBZ).(3) The radar's sensitivity is comparatively higher because the minimum radar reflectivity factor is about–35 dBZ in this experiment, which exceeds the threshold for detecting the linear depolarized ratio(LDR) of stratocumulus(commonly –11 to –14 dBZ; decreases with increasing turbulence).(4) After distinguishing of cloud droplets from drizzle, cloud liquid water content and particle effective radius are retrieved. The liquid water content of drizzle is lower than that of cloud droplets at the same radar reflectivity factor.  相似文献   

17.
“碧利斯”（2006）暴雨过程降水强度和降水效率分析   总被引：1，自引：1，他引：0  
刘圣楠  崔晓鹏 《大气科学》2018,42(1):192-208
利用2006年第4号强热带风暴“碧利斯”登陆过程的高分辨率数值模拟资料,结合三维地面降水诊断方程和降水效率公式,研究了“碧利斯”登陆后引发的局地暴雨过程,重点分析了此次局地暴雨过程的降水强度和降水效率及其与宏微观物理因子的联系。结果表明,降水强度越强,降水效率越高,但两者并非一一对应的线性关系,随着降水强度增大,降水效率增高的趋势逐渐变缓;伴随暴雨系统快速发展,降水强度和降水效率均显著增强,而主要降水源/汇项的时间变化要复杂得多;暴雨发生前时段与发生时段降水物理过程存在显著差异,发生前,较明显的水汽辐合显著加湿局地大气,并通过微物理转化支持降水云系发展,液相水凝物辐合对降水云系快速发展贡献明显,固相水凝物辐合贡献不显著,较强的“云滴与雨滴碰并（Pracw）”微物理过程同液相水凝物明显辐合可能有直接关系,“霰融化造成雨滴增长（Pgmlt）”仅为Pracw的27%,发生时段,进一步明显加强的水汽辐合依旧是主要降水来源,而汇项发生了明显变化,同时,微物理转化过程与发生前比更活跃,尤其是Pracw和Pgmlt,其中,Pgmlt增强更明显,其值接近Pracw的50%。  相似文献   

18.
为全面了解水汽在气溶胶影响雷暴云电过程中的作用,本研究在已有的二维雷暴云起、放电模式基础上,通过改变相对湿度和气溶胶初始浓度（文中气溶胶浓度均指气溶胶数浓度）进行敏感性数值模拟试验。结果表明:（1）随着气溶胶浓度升高,雷暴云产生更多的小云滴,降水过程受到抑制。而当水汽含量升高时,云滴数浓度的增长速度更快,雨滴数浓度升高,缓解了降水变弱的趋势。（2）水汽含量较低时,随着气溶胶浓度升高,更多小云滴被带入冻结层形成大量小冰晶,霰粒含量升高,雷暴云起电过程增强。气溶胶浓度升高至一定的量级（3000 cm?3）时,冰晶尺度减小和雨滴浓度降低抑制霰粒生长,雷暴云起电过程受到削弱。感应起电和非感应起电过程随气溶胶浓度升高呈先增强后减弱的趋势。水汽含量的升高促进了冰相粒子的增长,起电过程呈现持续增强的趋势,气溶胶浓度为3000 cm?3时起电率达到极值,电荷密度的增幅扩大。（3）水汽含量较低时,雷暴云难以发展成深厚的系统,气溶胶浓度变化对其影响不明显,电荷结构由三极性发展,在消散期演变为偶极性电荷结构;水汽含量较高时,雷暴云迅速发展成深厚的系统,随着气溶胶浓度升高,在雷暴发展旺盛阶段电荷分布表现为多层复杂结构。研究显示水汽含量在气溶胶浓度变化对雷暴云微物理、起电过程及电荷结构的作用中扮演重要角色。   相似文献   

19.
Raindrop size distribution (RSD) characteristics over the South China Sea (SCS) are examined with onboard Parsivel disdrometer measurements collected during marine surveys from 2012 to 2016. The observed rainfall is divided into pre-monsoon, monsoon, and post-monsoon periods based on the different large-scale circumstances. In addition to disdrometer data, sounding observation, FY-2E satellite, SPRINTARS (Spectral Radiation-Transport Model for Aerosol Species), and NCEP reanalysis datasets are used to illustrate the dynamical and microphysical characteristics associated with the rainfall in different periods. Significant variations have been observed in respect of raindrops among the three periods. Intercomparison reveals that small drops (D < 1 mm) are prevalent during pre-monsoon precipitation, whereas medium drops (1?3 mm) are predominant in monsoon precipitation. Overall, the post-monsoon precipitation is characterized by the least concentration of raindrops among the three periods. But, several large raindrops could also occur due to severe convective precipitation events in this period. Classification of the precipitation into stratiform and convective regimes shows that the lg(Nw) value of convective rainfall is the largest (smallest) in the pre-monsoon (post-monsoon) period, whereas the Dm value is the smallest (largest) in the pre-monsoon (post-monsoon) period. An inversion relationship between the coefficient A and the exponential b of the Z?R relationships for precipitation during the three periods is found. Empirical relations between Dm and the radar reflectivity factors at Ku and Ka bands are also derived to improve the rainfall retrieval algorithms over the SCS. Furthermore, the possible causative mechanisms for the significant RSD variability in different periods are also discussed with respect to warm and cold rain processes, raindrop evaporation, convective activities, and other meteorological factors.  相似文献   

20.
Millimeter-wavelength radar has proved to be an effective instrument for cloud observation and research. In this study, 8-mm-wavelength cloud radar (MMCR) with Doppler and polarization capabilities was used to investigate cloud dynamics in China for the first time. Its design, system specifications, calibration, and application in measuring clouds associated with typhoon are discussed in this article. The cloud radar measurements of radar reflectivity (Z), Doppler velocity (Vr), velocity spectrum width (Sw) and the depolar-ization ratio (LDR) at vertical incidence were used to analyze the microphysical and dynamic processes of the cloud system and precipitation associated with Typhoon Nuri, which occurred in southern China in August 2008. The results show the reflectivity observed using MMCR to be consistent with the echo height and the melting-layer location data obtained by the nearby China S-band new-generation weather radar (SA), but the Ka-band MMCR provided more detailed structural information about clouds and weak precipitation data than did the SA radar. The variation of radar reflectivity and LDR in vertical structure reveals the transformation of particle phase from ice to water. The vertical velocity and velocity spectrum width of MMCR observations indicate an updraft and strong turbulence in the stratiform cloud layer. MMCR provides a valuable new technology for meteorological research in China.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号