雷暴与强对流临近天气预报技术进展   总被引：81，自引：22，他引：59  

俞小鼎  周小刚  王秀明 《气象学报》2012,70(3):311-337

临近预报指0—6h(0—2h为重点)的高时空分辨率的天气预报,预报对象是该时段内出现明显变化的天气现象,主要包括雷暴、强对流、降水、冬季暴风雪、冻雨、沙尘暴、低能见度(雾)、天空云量等,其中,以雷暴和强对流天气的临近预报最具挑战性。综述了针对雷暴和强对流天气的以主观预报为主、结合客观算法的临近预报技术,同时讨论了高分辨率数值预报模式在临近预报中的应用。主观临近预报技术包括基于多普勒天气雷达观测数据并结合其他资料(常规高空和地面观测、气象卫星云图、快速同化循环的数值预报产品等)对雷暴生成、发展和衰减,特别是对强对流天气(包括强冰雹、龙卷、雷暴大风和对流性暴雨)的临近预报,客观算法包括几种应用最广的雷达回波或云图外推算法和强对流天气识别技术。高分辨率数值预报模式的应用包括与雷达回波外推融合延长临近预报时效,与各种观测资料融合得到快速更新的三维格点资料为雷暴和强对流近风暴环境的判断提供重要参考。  相似文献   

一次强飑线云结构特征的卫星反演分析   总被引：1，自引：0，他引：1  

徐小红  余兴  朱延年  刘贵华  戴进  岳治国 《高原气象》2012,31(1):258-268

利用NOAA卫星AVHRR资料,对2006年4月28日山东一次春季强飑线过程进行了分析,重点研究了卫星资料多光谱综合分析的强对流云微物理特征和卫星识别的对流强信号,并与雷达、FY-2C卫星观测资料进行了对比分析。结果表明:(1)RGB合成图能清晰地显示云顶的结构、纹理、云砧、组成、高度及云厚等信息,是一种很方便的分析工具。(2)多光谱综合分析归纳出卫星探测对流强信号:云顶的对流结构和纹理突出,有明显的云砧,云顶以小粒子为主,粒子有效半径Re随高度增长缓慢,云团上部存在明显的Re随高度递减带,云顶Re和-dRe/dT能定量指示对流的强弱。据此,卫星识别出强中心A比实际降雹提前了近1h,比飑线发生提前了2.5h,比多普勒雷达监测提前了近2h,特别是识别出的强中心B比实际降雹提前了近4h。卫星探测为强对流天气的监测预报和预警提供了一种新途径。  相似文献   

NCEP再分析资料在强对流环境分析中的应用   总被引：11，自引：3，他引：8       下载免费PDF全文

王秀明  俞小鼎  朱禾 《应用气象学报》2012,23(2):139-146

为考察NCEP再分析资料在我国强对流天气产生环境分析中的适用性,选取2002—2009年多普勒天气雷达识别的60例超级单体风暴个例,对比分析常规探空资料和NCEP再分析资料提取的温、湿、风垂直廓线,结果表明:NCEP再分析资料计算的对流有效位能因对抬升气团湿度敏感而与观测间差异较大,宜用K指数、温度直减率分析大气层结稳定度;因对流层中高层风与探空差异不大,其中500~700 hPa的风与探空近乎一致,因此NCEP再分析资料计算的深层、中层风垂直切变参量可靠性较高;NCEP再分析资料水汽参数与探空资料差异大,特别是在大气边界层,需用观测资料订正;边界层物理量,特别是风向与探空差异显著,因此不宜用NCEP再分析资料讨论雷暴触发问题;平均而言,NCEP再分析资料湿度廓线低层偏干而中层偏湿,925 hPa以上风速偏小,降低了强对流发生概率。  相似文献   

ASYMMETRIC DISTRIBUTION OF CONVECTION ASSOCIATED WITH TROPICAL CYCLONES MAKING LANDFALL ON THE EAST CHINA COAST   总被引：1，自引：1，他引：0  

朱佩君  郑永光  郑沛群 《热带气象学报(英文版)》2012,18(4):436-444

The asymmetric distribution of convection associated with tropical cyclones making landfall on the east China coast is studied with black-body temperature (TBB) data from Fengyun-2 (FY-2) geostationary weather satellite. The convection in various quadrants of the TCs is examined for the period of -24 to 6 h relative to landfall. The convection to the southern side of the TCs was much more intense than that to the northern side during the whole landfall period. The convection to the western side of the TCs was stronger than that to the eastern side for the time -8 h before and at the landfall. After landfall, the situation reverses. The asymmetric convection of the TCs was partly due to the vertical wind shear and storm motion, and partly because the process of landfall restrained the convection in relevant quadrants. Besides, the orographic uplift along the east of China was favorable to the enhancement of convection in the eastern side of the TCs. From the characteristics of convective asymmetry of the TCs landing on the south and east of China, it is known that their main difference might be the included angle between the TC path and the coastline as well as the terrain along the coast.  相似文献   

西北地区退耕还林对区域气候的影响     

薛小宁  刘敏  张桂梅 《陕西气象》2010,(2):1-7

利用NCEP再分析资料对2009年3月20日夜至21日凌晨豫北强对流天气过程进行了分析,结果表明：①导致这次强对流天气发生的湿位涡场分布特征为,对流层低层MPV1〉0,同时MPV2〈0;强对流发生时,对流高层表现为MPV1〉0,同时MPV2〈0,即高低层均为异常的湿对流稳定区。②强对流的发生发展与湿位涡的时空演变有着很好的对应关系,对流层高低层湿位涡“正负区垂直叠加”的配置是强对流天气发展的有利形势。这次强对流天气发生在低层湿位涡正压项等值线密集的零线附近以及大于零的区域和湿位涡斜压项的负值区,同时高层为湿位涡正压项等值线密集正值区域和湿位涡斜压项的负值区。③中低层急流和地面东路冷空气入侵高温高湿不稳定区是形成这次强对流天气的主要原因,中尺度对流云团是造成此次强对流天气的直接影响系统,且强对流发生前,近地面存在逆温层。  相似文献   

A NUMERICAL STUDY OF TROPICAL DEEP CONVECTION USING WRF MODEL   总被引：1，自引：0，他引：1  

李嘉鹏  银燕  金莲姬  张成竹 《热带气象学报(英文版)》2010,16(3):247-254

The Weather Research Forecast model (WRF) configured with high resolution and NCEP 1°×1° reanalysis data were used to simulate the development of a tropical deep convection over the Tiwi Islands,northern Australia,and to investigate the sensitivity of model results to model configuration and parameterization schemes of microphysical processes.The simulation results were compared with available measurements.The results show that the model can reproduce most of the important characteristics of the observed diurnal evolution of the convection,including the initiation of convection along the sea-breeze front,which is then reinforced by downdraft outflows,merging of cells and the formation of a deep convective system.However,further improvement is needed to simulate more accurately the location and the time for initiation of the deep convective system.Sensitivity tests show that double-nesting schemes are more accurate than the non-nesting schemes in predicting the distribution and intensity of precipitation as far as this particular case is concerned.Additionally,microphysical schemes also have an effect on the simulated amount of precipitation.It is shown that the best agreement is reached between the simulation results and observations when the Purdue Lin scheme is used.  相似文献   

OBSERVATIONAL ANALYSIS OF ASYMMETRIC DISTRIBUTION OF CONVECTION ASSOCIATED WITH TROPICAL CYCLONES “CHANCHU” AND “PRAPIROON” MAKING LANDFALL ALONG THE SOUTH CHINA COAST   总被引：2，自引：1，他引：1  

袁金南  周文  黄辉军  廖菲 《热带气象学报(英文版)》2010,16(2):171-180

Observational data of mesoscale surface weather stations and weather radars of Guangdong province are employed to analyze the asymmetric distribution of convection prior to, during and after landfall for tropical cyclones of Chanchu and Prapiroon making landfall on the south China coast in 2006. The results showed that strong convection is located in the eastern and northern sectors of the landfalling Chanchu and Prapiroon, namely in the front and right portions of the TC tracks, for a period of time starting from 12 h prior to landfall to 6 h after it. Their convection also had distinct differences in the vertical direction. The analysis indicated that although the landfall of Chanchu and Prapiroon has the same asymmetric distribution of convection, the causes are not exactly the same. The asymmetric distribution of convection in the case of Chanchu is mainly correlated with the impacts of a strong environmental vertical wind shear, low-level horizontal wind shear, and low-level convergence and divergence. In the case of Prapiroon, however, the asymmetric distribution of convection is mainly associated with the impacts of low-level convergence and divergence.  相似文献   

Teleconnection Patterns along the Asian Jet Associated with Different Combinations of Convection Oscillations over the Indian Continent and Western North Pacific during Summer   总被引：1，自引：0，他引：1       下载免费PDF全文

SHI Shan-Feng  LU Ri-Yu 《大气和海洋科学快报》2010,3(1):14-18

A zonal teleconnection has been found along the Asian jet over the Eurasian continent during summer.In this study,the authors investigated circulation anomalies in the extratropics,in particular for the zonal teleconnection,under different combinations of subtropical convection anomalies over the northern Indian continent (IND) and the western North Pacific (WNP).The outof-phase configuration (i.e.,stronger (weaker) IND convection and weaker (stronger) WNP convection) was found to be more common than the in-phase configuration (i.e.,stronger (weaker) IND convection and stronger (weaker) WNP convection),which is consistent with previous results.Composite results indicated that circulation anomalies for out-of-phase configurations of 30-60-day convection oscillations are much stronger in the middle latitudes than those for in-phase configurations.In addition,zonal teleconnection patterns are predominant for the out-of-phase configurations,particularly for the configuration of strong IND convection and weak WNP convection;however,they are either weak or obscure for the in-phase configurations.These results suggest that the zonal teleconnection pattern along the Asian jet is dependent on different combinations of the IND and WNP subtropical convection anomalies.  相似文献   

用多普勒雷达对三次强对流天气的短时预报对比分析   总被引：2，自引：0，他引：2  

吕江津  刘一玮  王彦 《气象》2009,35(1):48-54

利用2006年6月12日夜间、7月12日凌晨和7月12日夜间天津地区3次强对流降水过程的多普勒雷达产品资料,对比分析发现:在降水的开始和成熟阶段,多普勒雷达径向速度场的变化一般先于回波强度场的变化,在做降水短时预报时应重点关注多普勒雷达径向速度场的变化,同时还可参考Auto-nowcaster系统的预报结果,通过判断未来雷达回波的强度变化及移动方向,提高对强对流降水过程的短时预报准确率.  相似文献   

The Variations of Dominant Convection Modes over Asia, Indian Ocean, and Western Pacific Ocean during the Summers of 1997--2004     

LI Yuefeng  XIAO Ziniu  JU Jianhu  Guoquan Hu 《大气科学进展》2010,27(4):901-920

The NOAA daily outgoing longwave radiation (OLR) and the Global Precipitation Climatology Project （GPCP） daily precipitation data are used to study the variation of dominant convection modes and their relationships over Asia, the Indian Ocean, and the western Pacific Ocean during the summers from 1997 to 2004. Major findings are as follows: (1) Regression analysis with the OLR indicates the convective variations over Asian monsoon region are more closely associated with the convective activities over the western subtropical Pacific (WSP) than with those over the northern tropical Indian Ocean (NTIO). (2) The EOF analysis of OLR indicates the first mode (EOF1) exhibits the out-of-phase variations between eastern China and India, and between eastern China and the WSP. The OLR EOF1 primarily exhibits seasonal and even longer-term variations. (3) The OLR EOF2 mostly displays in-phase convective variations over India, the Bay of Bengal, and southeastern China. A wavelet analysis reveals intraseasonal variation (ISV) features in 2000, 2001, 2002, and 2004. However, the effective ISV does not take place in every year and it seems to occur only when the centers of an east--west oriented dipole reach enough intensity over the tropical Indian and western Pacific Oceans. (4) The spatial patterns of OLR EOF3 are more complicated than those of EOF1 and EOF2, and an effective ISV is noted from 1999 to 2004. The OLR EOF3 implies there is added complexity of the OLR pattern when the effective ISV occurs. (5) The correlation analysis suggests the precipitation over India is more closely associated with the ISV, seasonal variations, and even longer-term variations than precipitation occurring over eastern China.  相似文献