UPGRADING OF TROPICAL LIMITED-AREA NUMERICAL MODEL AND APPLICATION IN TYPHOON FORECAST     

薛纪善  王康玲  何安国 《热带气象学报(英文版)》1996,2(2):120-128

A new tropical limited-area numerical model system developed in recent years is described in detail,which includes model formulation, physical processes and data initialization. Results of the application in numerical forecast from 1993 to 1995 are presented. In the forecast of typhoon, the new system shows a distinct improvement over a previous one.  相似文献   

两次龙舟水降水过程中不同类型的天气雷达特征分析     

庞古乾  伍志方  谌志刚  刘运策 《广东气象》2014,36(6):1-5

对2013年5月20日和5月22日由南海季风造成的两次龙舟水过程进行了多普勒雷达资料分析,结果表明:造成雷雨大风的飑线过程具有人字形特征,之后分裂为两条弓形回波,此飑线具有前倾结构、高质心高度、高VIL、共存多个中气旋、中层径向辐合、速度模糊等特点,雷雨大风是由飑线前后两侧的下击暴流造成的;形成列车效应的带状回波具有低回波顶高、低质心高度、中气旋、急流核高度低等特点,短时强降水中局部地区的大风是由环境风造成。  相似文献   

Parameterization and Application of Storm Surge/Tide Modeling Using a Genetic Algorithm for Typhoon Periods     

Sung Hyup YOU  Yong Hee LEE  Woo Jeong LEE 《大气科学进展》2011,28(5):1067-1076

A genetic algorithm was used to optimize the parameters of the two-dimensional Storm Surge/Tide Operational Model (STORM) to improve sea level predictions.The genetic algorithm was applied to nine typhoons that affected the Korean Peninsula during 2005-2007.The following model parameters were used:the bottom drag coefficient,the background horizontal diffusivity,Smagorinski’s horizontal viscosity,and the sea level pressure scaling.Generally,the simulation results using the optimized,mean,and median parameter values improved sea level predictions.The four estimated parameters improved the sea level prediction by 76% and 54% in the bias and root mean square error for Typhoon Kalmaegi (0807) in 2008,respectively.One-month simulations of February and August 2008 were also improved using the estimated parameters.This study demonstrates that parameter optimization on STORM can improve sea level prediction.  相似文献   

Impact of Cloud Microphysical Processes on the Simulation of Typhoon Rananim near Shore.Part Ⅰ: Cloud Structure and Precipitation Features     

程锐  宇如聪  傅云飞  徐幼平 《气象学报》2011,25(4)

By using the Advanced Regional Eta-coordinate Model (AREM),the basic structure and cloud features of Typhoon Rananim are simulated and verified against observations.Five sets of experiments are designed to investigate the effects of the cloud microphysical processes on the model cloud structure and precipitation features.The importance of the ice-phase microphysics,the cooling effect related to microphysical characteristics change,and the influence of terminal velocity of graupel are examined.The results indicate that the cloud microphysical processes impact more on the cloud development and precipitation features of the typhoon than on its intensity and track.Big differences in the distribution pattern and content of hydrometeors,and types and amount of rainfall occur in the five experiments,resulting in different heating and cooling effects.The largest difference of 24-h rain rate reaches 52.5 mm h-1.The results are summarized as follows:1) when the cooling effect due to the evaporation of rain water is excluded,updrafts in the typhoon's inner core are the strongest with the maximum vertical velocity of-19 Pa s-1 and rain water and graupel grow most dominantly with their mixing ratios increased by 1.8 and 2.5 g kg-1,respectively,compared with the control experiment; 2) the melting of snow and graupel affects the growth of rain water mainly in the spiral rainbands,but much less significantly in the eyewall area; 3) the warm cloud microphysical process produces the smallest rainfall area and the largest percentage of convective precipitation (63.19％),while the largest rainfall area and the smallest percentage of convective precipitation (48.85％) are generated when the terminal velocity of graupel is weakened by half.  相似文献   

The T-TREC Technique for Retrieving the Winds of Landfalling Typhoons in China   总被引：1，自引：1，他引：0       下载免费PDF全文

WANG Mingjun  ZHAO Kun  WU Dan 《Acta Meteorologica Sinica》2011,25(1):91-103

In this study, an extension of the TREC (Tracking Radar Echo by Correlations) technique, named Tropical Cyclone (TC) circulation TREC (T-TREC), is developed to retrieve the winds of landfalling typhoons in China. The T-TREC analysis is performed on a polar grid centered at the TC center, using arc-shaped correlation cells and an arc-shaped search area. The search for the best correlation match is confined along the cyclonic direction with a limited search distance in the radial direction based on the cyclonic circulation characteristics of TCs in the Northern Hemisphere. The TC center is determined objectively using reflectivity data while the Doppler radar radial velocities are incorporated to estimate the search range and create a velocity correlation matrix as auxiliary constraints.  相似文献   

强冰雹和短时强降水天气雷达特征及临近预警   总被引：10，自引：2，他引：8  

李德俊  唐仁茂  熊守权  柳草  向玉春  袁正腾  王慧娟  韩琦 《气象》2011,37(4):474-480

利用恩施多普勒雷达和常规分析资料,详细对比分析了2007-2008年发生在恩施山区强冰雹和短时强降水天气过程中的雷达产品特征.在此基础上,找出了适合恩施山区强冰雹和短时强降水天气的雷达临近预警指标:选取负温区回波厚度≥7 km、CR强中心回波强度≥55 dBz、强回波梯度≥15 dBz·km-1、45 dBz强回波伸展高度≥7.5 km、累积液态含水量(VIL)密度≥3.2 g·m-3和雷达风廓线1.8～6.1 km风垂直切变均值≥2.3×10-3s-1作为强冰雹临近预警指标;当满足组合反射率(CR)强中心回波强度、VIL密度、40 dBz强回波伸展高度和雷达风廓线(VWP)上1.8～6.1 km风垂直切变值达43.0 dBz,1.1 g·m-3,7.0 km和1.9×10-3s-1,可以考虑该站点及附近地区进入短时强降水临近预警状态,并利用2009年发生的强冰雹和短时强降水天气过程检验了这些临近预警指标性能.  相似文献   

2010年11月大气环流和天气分析   总被引：1，自引：0，他引：1  

于超 《气象》2011,37(2):242-248

2010年11月大气环流主要特征是:北半球高纬度地区为单一极涡,极涡中心位于新地岛以北,强度比常年略偏强.中高纬环流呈三波型分布,其中欧洲大槽较常年同期偏强,东亚大槽强度接近常年同期.亚洲以正高度距平为主,只有西伯利亚地区呈现负距平,表明冷空气势力较常年同期偏弱.西北太平洋副热带高压面积接近常年同期,强度略偏弱,脊线位...  相似文献   

桂西北一次超级单体风暴过程的分析   总被引：2，自引：0，他引：2  

农孟松  祁丽燕  黄海洪  邓汝伊  班荣贵 《气象》2011,37(12):1519-1525

本文利用常规观测资料和多普勒天气雷达资料,对2009年4月12日发生在广西西北部的大范围冰雹天气进行分析,得出以下结论：（1）导致冰雹发生的天气系统是高空低涡和低层切变线,冰雹发生前上午百色探空站有中等对流有效位能、上干下湿层结结构、强的深层垂直环境风切变,速度矢图上低层强的顺时针旋转曲率,已经具备强对流潜势发生条件。（2）超级单体右前方的低层反射率因子呈现明显的钩状回波,是超级单体风暴的典型特征之一。反射率因子垂直剖面呈现出典型的有界弱回波区、回波悬垂和回波墙。最大的回波强度出现在沿着回波墙的一个竖直的狭长区域,其值超过65 dBz。相应的中低层径向速度图呈现一个中等强度的中气旋,旋转速度达到22 m·s-;垂直累积液态水含量和密度分别超过70kg·m~（-2）和5 g·m~（-3）。（3）高空低涡正涡度区、高CAPE值、地面辐合线在右江河谷滞留以及特殊地形作用,是多个对流单体沿相似路径移动的主要原因。  相似文献   

基于配料法的“08.6.3”河南强对流天气分析和短时预报   总被引：5，自引：1，他引：4  

吴蓁  俞小鼎  席世平  徐文明 《气象》2011,37(1):48-58

采用基于构成要素的预报方法(配料法),使用业务中能够及时获取的常规观测资料、静止气象卫星云图和多普勒天气雷达资料,对2008年6月3日下午发生在河南大部的以雷暴大风为主的强对流天气进行分析.针对2008年6月3日08时500、700、850 hPa和地面图上温、湿、风等的配置,结合探空、水汽云图和多普勒天气雷达回波图,对构成强对流天气的几个主要因素:层结稳定度、水汽、触发机制、垂直风切变、对流层干层等进行分析,结果表明:河南大部处于较强的条件不稳定、强烈的深层(地面到500 hPa)垂直风切变和明显的高空干平流的环境中,这种环境有利于高度组织性的超级单体风暴的产生和发展,导致雷暴大风和冰雹天气.而地面冷锋、辐合线和高空次天气尺度涡旋伴随的正涡度平流共同作用产生的上升气流导致雷暴在山西中南部生成,然后向东南方向移下太行山.进入河南有利的环境下获得猛烈发展.在充分利用"配料法"的主要思路和现有观测资料条件下,结合预报经验,2008年6月3日强对流过程可以提前数小时进行正确的短时预报.  相似文献   

0801号台风风浪场和涌浪场的数值模拟     

韩晓伟  周林  游大鸣  萧中乐 《南京气象学院学报》2011,34(5):597-605

利用美国国家海洋大气总局/美国国家环境预报中心（NOAA/NCEP）发布的最新版WAV-EWATCHⅢ（version3.14）海浪模式对0801号台风＂浣熊＂进行数值模拟,并在此基础上对台风浪的发展过程和台风影响下的海面有效波高、风浪场及涌浪场的分布特征进行分析。结果表明：海面有效波高的分布和演变受台风系统强度和移动的影响;台风过程中所产生的大浪主要为风浪;涌浪场的分布与风浪场的分布几乎相反,涌浪场基本分布在远离台风中心的外围海域;涌浪场波高比风浪场波高要小。  相似文献