山西高温天气的环流特征及流型配置研究     

苗爱梅  贾利冬  李苗  范光海 《山西气象》2011,(1):4-11

利用1958年-2008年高低空气象观测资料以及山西省气象信息中心归档的109站1958年-2008年的原始气象记录月报表及其信息化产品资料,分别以最高气温≥35℃、≥37℃、≥40℃为指标,研究山西高温日的时空分布、变化趋势及环流特征。结果表明：a）山西高温日最早出现在4月中旬,最晚出现在9月中旬,≥35℃、≥37℃和≥40℃的高温日6月下旬最多;b）高温日数有随纬度、随海拔的升高而减少,有西部多于东部、南部多于北部、盆地多于山区的空间分布特征。≥40℃的高温区域主要集中在运城和临汾地区;C）1984年-2008年,35℃以上的高温日数整体呈上升趋势;1979年-2008年,30年间高温站次以153站次,10a的趋势增多。20世纪90年代以后,不仅高温日数增多,而且高温持续时间、强度、范围都有增强趋势;d）影响山西高温的500hPa环流形势主要有副高纬向性、副高经向型以及大陆高压（脊）控制型3类。在特定的流型配置下,T850≥25℃、T700≥13℃,T850≥26℃、T700≥14℃,T850≥28℃、T700≥15℃,T850≥32℃、T700≥16℃是山西省不同区域、不同风向影响时,≥35℃、≥37℃、≥40℃高温天气预报的临界值。  相似文献   

粤西北霜日的年际变化与大气环流异常的关系     

李丽  简茂球 《热带气象学报》2011,27(1):101-108

利用1964-2006年测站观测资料和NCEP/NCAR再分析资料分析了粤西北霜日的年际变化特征,及其与大气环流异常的联系.结果表明:粤西北的霜日主要集中于12月和1月;从1986年之后年霜日呈明显的递减趋势.并且粤西北的西部和南部线性递减较快;粤西北地区12月和1月霜日偏多、偏少年的大气环流异常特征相似;12月和1月...  相似文献   

２００２年海南一次非热带气旋暴雨成因分析     

吴春娃  赵付竹  王凡 《陕西气象》2011,(2):1-3

本文对2008年8月10日出现在北京首都机场的一次暴雨天气过程,从天气形势、物理量场、卫星产品、雷达资料等多方面进行了分析,结果表明,此次强降水发生在高空有利的环流背景下,锋面抬升、高低层温度差动平流、中层辐合、中低层风切变、中层暖干盖的存在以及副高的维持均为强降水的产生提供了有利条件。  相似文献   

Analysis on structure of Typhoon Longwang based on GPS dropwinsonde data   总被引：1，自引：1，他引：0  

舒守娟  彭犁然 《热带气象学报(英文版)》2011,17(3):193-201

As one of the most severe typhoons in the year 2005,Typhoon Longwang is chosen as a case study in this article.Throughout its life,two surveillance flights are carried out on it.Different from previous studies,GPS(global positioning system)Dropwinsonde data collected from the Dropwinsonde Observations for Typhoon Surveillance near the Taiwan Region is chosen to present the thermodynamic and kinetic structure at its two different stages of development.This study suggests that not only kinetic structure but also thermodynamic structure of Longwang are more robust in the second surveillance than the first surveillance,with stronger and larger circulation and a warmer core.Further research shows that the environmental vertical wind shear mainly contributes to the asymmetric structure of the typhoon.The strong vertical wind shear not only results in the distinct asymmetric structure,but also restrains the development of the typhoon.  相似文献   

ENSO事件对云南及临近地区春末初夏降水的影响   总被引：3，自引：0，他引：3  

杨亚力  杜岩  陈海山 《大气科学》2011,35(4):729-738

本文采用合成及相关分析的方法,应用55年中国降水资料、美国NOAA海表温度资料以及NCEP/NCAR再分析资料,研究了ENSO事件对我国云南及其邻近地区春末初夏降水的影响及物理机理.研究结果表明:(1)在El Ni(n)o (La Ni(n)a)年,云南大部分地区4～5月降水偏少(多),东部地区相关信号尤其明显;(2)...  相似文献   

Asymmetric rainband breaking in Typhoon Haitang (2005) before and after its landfall   总被引：1，自引：1，他引：0  

丁治英  王勇  沈新勇  徐海明 《热带气象学报(英文版)》2011,17(3):276-284

Using the WRF (Weather Research Forecast) model, this work performed analysis and simulation on the rainband change during the landfall of Typhoon Haitang (2005) and found that breaking may occur over land and oceans leads to distinct asymmetric precipitation. The breaking is related to the topographic effect as well as interactions between the typhoon and midlatitude systems at upper levels. During the landfall, divergent flows at the 200-hPa level of the South-Asian high combined with divergent flows at the periphery of the typhoon to form a weak, inverted trough in the northwest part of the storm, with the mid- and low-level divergence fields on the west and northwest side of the typhoon center maintaining steadily. It intensifies the upper-level cyclonic flows, in association with positive vorticity rotating counterclockwise together with air currents that travel stepwise into a vorticity zone in the vicinity of the typhoon core, thereby forming a vorticity transfer belt in 22–25? N that extends to the eastern part of the storm. It is right here that the high-level vorticity band is subsiding so that rainfall is prevented from developing, resulting in the rainbelt breaking, which is the principal cause of asymmetric precipitation occurrence. Migrating into its outer region, the banded vorticity of Haitang at high levels causes further amplification of the cyclonic circulation in the western part and transfer of positive vorticity into the typhoon such that the rainband breaking is more distinct.  相似文献   

与西澳州西南部冬季降水相联系的大气环流特征分析     

李建平  李艳杰  冯娟 《大气科学》2011,35(5):801-817

西澳大利亚州西南部(SWWA)是西澳大利亚州首府Perth的所在地,也是西澳州政治、经济、文化、教育和旅游的中心.自20世纪中期以来,SWWA地区雨季降水持续减少.本文利用近60年的观测及再分析数据,分析了已知的影响澳大利亚降水的热带海洋模态:厄尔尼诺—南方涛动(ENSO)、印度洋偶极子(IOD)和ENSOModoki...  相似文献   

非地转湿Q矢量在台风暴雨预报中的应用试验     

张亚洲  邵邹  邓文彬  赵文斌 《气象与减灾研究》2011,(4):23-29

利用NCEP/NCAR全球格点资料和TRMM卫星资料,采用改进后的非地转湿Q矢量,对0908号台风“莫拉克”引起的台湾南部特大暴雨过程进行预报应用试验.试验结果表明:(1) 850hPa高度层的非地转湿Q矢量散度及水汽通量散度分布可以预报未来24 h暴雨的落区及其雨带的分布,暴雨发生在Q矢量散度梯度大值区靠近辐合区域,...  相似文献   

Determination of onset date of the South China Sea summer monsoon in 2006 using large-scale circulations   总被引：1，自引：1，他引：0  

郑彬  林爱兰  谷德军  李春晖 《热带气象学报(英文版)》2011,17(3):202-208

Since the South China Sea (SCS) summer monsoon (SCSSM) is pronouncedly featured by abruptly intensified southwesterly and obviously increased precipitation over the SCS,the lower-tropospheric winds and/or convection intensities are widely used to determine the SCSSM onset.The methods can be used successfully in most of the years but not in 2006.Due to the intrusion of Typhoon Chanchu(0601)that year,the usual method of determining SCSSM onset date by utilizing the SCS regional indices is less capable of pinpointing the real onset date.In order to solve the problem,larger-scale situations have to be taken into account.Zonal and meridional circulations would be better to determine the break-out date of SCSSM in 2006.The result indicates that its onset date is May 16.Moreover,similar onset dates for other years can be obtained using various methods,implying that large-scale zonal and meridional circulations can be used as an alternative method for determining the SCSSM onset date.  相似文献   

21个气候模式对东亚夏季环流模拟的评估II:年际变化   总被引：4，自引：2，他引：2  

张宏芳  陈海山 《气象科学》2011,31(3):247-257

利用欧洲中期天气预报中心的ERA40再分析资料, 评估了参与政府间气候变化专门委员会第四次评估报告的21个全球海气耦合模式对东亚地区夏季大气环流年际变率的模拟能力,结果表明：（1）模式对东亚地区不同要素的年际变率模拟能力整体偏弱, 500 hPa高度场的模拟能力总体优于海平面气压场及850 hPa风场;（2）两大环流系统年际变率的模拟结果评估表明：就相关系数而言,副高强度、面积的模拟能力优于印度低压,多数模式能正确模拟出副高1970s后期增强的趋势;就标准差来看,模式对印度低压、印度低压东伸槽模拟效果相对较好;（3）评估三种季风指数的模拟能力结果显示,环流异常指数模拟效果略好,但多数模式都不能模拟出海陆气压差、经向风、环流异常季风指数的年际变化。  相似文献