首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 109 毫秒
1.
广东后汛期季风槽暴雨天气形势特征分析   总被引:19,自引:2,他引:17  
黄忠  张东  林良勋 《气象》2005,31(9):19-24
对1981-2002年广东后汛期季风槽暴雨期间的环流形势和天气系统进行了统计分析,结果发现,广东后汛期的季风槽暴雨多数发生在西太平洋副高位置偏东或偏南的情况下,并与中纬西风槽或ITCZ有直接联系;季风槽多数位于华南地区上空或华南沿岸海面;高层辐散覆盖广东全部或大部,中心在华南近海。西南季风向北推进源于西南和华南地区低压槽发展,或由于热带气旋登陆后北上而牵动西南季风深入华南陆地,也有些过程是副高西端的偏南气流引导南海季风北进。对流活动有从南海北部或北部湾附近向华南移动的趋势,并有昼夜变化。  相似文献   

2.
南海季风槽影响下热带气旋暴雨增幅的研究   总被引:8,自引:1,他引:7  
卢山  吴乃庚  薛登智 《气象》2008,34(6):53-59
使用NASA的热带测雨卫星TRMM资料、常规气象观测降水资料、NCAR/NCEP-2再分析资料及NCEP全球数据同化系统(GDAS)资料,分析研究南海季风槽伴随热带气旋登陆华南而导致热带气旋暴雨强烈增幅的事实,并根据观测事实提出季风槽伴随热带气旋登陆华南的定义.结果表明:(1)南海季风槽伴随热带气旋登陆导致热带气旋降水强烈增幅的天气现象发生在盛夏季节;(2)环流背景表现为副热带高压带状西伸,稳定控制华中一带;同时,西南季风活跃,南海季风槽位于南海北部之时;(3)热带气旋登陆后的填塞消亡时间因为季风槽的伴随而大大延长,热带气旋云系有再生、加强和扩展现象;(4)伴随登陆的季风槽对热带气旋暴雨无论是空间,时间,还是强度上均有强烈增幅作用,热带气旋暴雨在季风槽南侧延伸,尺度可达1500~2500km.  相似文献   

3.
利用南海季风试验研究(1997~2000)的成果资料,对强弱南海夏季风年广西的天气作了对比研究,主要分析了雨季开始、年雨量分配及丰欠、热带气旋活动特点等方面的差异并归纳出一个简单的预测概念模型,可供业务工作者在制作年景预测上参考。  相似文献   

4.
强弱南海夏季风年广西的天气及预测概念模型   总被引:4,自引:0,他引:4  
利用南海季风试验研究(1997-2000)的成果资料,对强弱南海夏季风年广西的天气作了对比研究,主要分析了雨季开始、年雨量分配及丰欠、热带气旋活动特点等方面的差异并归纳出一个简单的预测概念模型,可供业务工作者在制作年景预测上参考。  相似文献   

5.
林志强 《广东气象》1997,(3):29-30,4
1996年西太平洋共生成热带气旋30个,属正常年份。全年登陆我国的热带气旋共7个(见表1),属偏少年份。其中,在广东省登陆的有2个,较多年平均热带气旋登陆广东的个数明显偏少。11996年影响广东省热带气旋的特点分析初台特迟一9月9日在吴川市沿海登陆的9615号台风,是建国以来登陆广东省最迟的初台。比以前最迟的初台登陆时间(1975年8月14日7506号台风在斗门县登陆)还晚二十多天。在南海活动的热带气旋个数多一本年度在南海海面形成或进入南海海面活动的热带低压共有5个,它们的序号分别是第1、第13、第18涕24和第刀。此外,还有进入南…  相似文献   

6.
利用NECP/NCAR再分析资料和茂名地区观测站1974—2013年降水资料,运用相关分析等统计方法,探讨近40年来西南季风强弱与茂名降水的关系。结果表明:南海西南季风强度对茂名汛期、年降水量的影响有非对称性,南海西南季风强,茂名汛期、年降水较常年偏多;西南季风弱,茂名降水不确定,各月规律不同。西南季风强度与茂名某些月份尺度的相关性比季、年尺度的相关性较好,特别是冬季月份。近40年茂名暴雨日分布表现为单峰型,暴雨集中在5—9月,7月为峰值;各季风年极端降水多发的月份不同,强季风年为4—9月、正常年为5—8月、弱季风年为5—9月。强季风年极端降水发生的概率大于其它年份,正常年极端降水发生的概率较小。  相似文献   

7.
2014年广东省气候概况   总被引:1,自引:0,他引:1  
2014年广东全省平均气温22.1℃,较常年和2013年均偏高0.2℃,其中夏秋季平均气温创历史新高。全省平均降水量1 652.5 mm,较常年偏少7.6%,比2013年偏少472 mm;但降水时空分布不均,前汛期多后汛期少,粤东北部和西南部少,其余地区多。全省平均高温日数为31.5 d,较常年偏多14 d,为有气象记录以来最多。2月,东亚冬季风偏强;夏秋季西北太平洋副热带高压明显偏强、偏西、偏南;南海夏季风爆发晚,结束正常,强度较常年略偏弱。3月30日全省开汛,较常年偏早7d。全年有4个热带气旋登陆广东省,接近常年情况,其中登陆徐闻的"威马逊"为1949年以来登陆广东省的最强台风。总体来看,2014年广东省属于一般偏差气候年景。  相似文献   

8.
夏季广东降水异常变化与夏季风   总被引:19,自引:14,他引:19  
利用广东省36个地面站降水量资料和NCEP850hPa再分析资料,采用相关分析和合成对比分析方法,探讨了广东降水变化与夏季季风活动的关系。发现广东夏季降水量变化与南海北部西南风大小成显著正相关,但并不能由此得出南海北部西南季风强广东降水多的结论。前汛期(4-6月),西南季风可以给广东带来降水,但降水的变化与西南季风强度变化关系不显著,5-6月份甚至出现热带西南季风弱广东降水反而强的情况,其主要的影响来自于副热带季风的加强。后汛期(7-9月),当西南季风在南海中北部地区加强,副热带季风对广东影响减弱时,广东降水增大。  相似文献   

9.
2009年广东省汛期降水空间分布不均的气候成因   总被引:3,自引:3,他引:0  
2009年广东省汛期(4~9月)降水呈现出空间分布不一致性,采用统计方法分析引起这种现象的成因:直接原因是大气环流异常导致了季风爆发偏晚和冷空气偏弱,从而前汛期降水大部分地区偏少;而后汛期期间西太平洋副热带高压偏西偏强,导致热带气旋主要登陆及影响珠江口和粤西地区,从而后汛期降水雨带主要位于粤西南。因而,2009年汛期多种环流因素的共同作用,导致了珠江口及其以西降水偏多,其余地区降水偏少。  相似文献   

10.
影响广西的热带气旋与热带季风的某些关系   总被引:11,自引:1,他引:11  
吴恒强 《气象》2002,28(9):27-32
利用常规的热带气旋气候资料和最近(1998)实施的南海季风试验研究成果资料,统计分析影响广西的热带气旋活动与热带季风爆发迟早,强弱等变异的关系,揭示了一些统计特征,并探讨其中的某些规律,初步分析了热带季风对热带气旋的作用,指出热带季风气流进入热带气旋环流对热带气旋的发展有正贡献。  相似文献   

11.
The activity of South China Sea southwest monsoon (SCSSM) has direct impacts on the anomalies of important weather in Guangdong province during the raining seasons. So it is necessary to explore thoroughly the activity pattern of SCSSM and its relationship with important weather anomalies in the province. In this paper, the methods of composite analysis and correlation statistics are used to study the relationship between the onset date and intensity of SCSSM and the important weather, such as precipitation trends in Guangdong province during the annually first and second raining seasons, the timing of the annually first and last typhoon and the number of typhoons landing in Guangdong province. The results show that the rainfall is less than normal during the first raining season, but more than normal during the second one and there are more tropical cyclones landing in Guangdong province in the years of early SCSSM onset. The rainfall is more than normal during the second raining season and there are more tropical cyclones landing in Guangdong province in the years of strong SCSSM. The relationship between the SST of April - June, July - September and previous winter (December - February) and 500 hPa geopotential height and the onset date and intensity of SCSSM is analyzed. Some mechanisms between the onset dates and intensity of SCSSM and the important weather anomalies in Guangdong province are preliminarily explored. The results can be used for reference in short-term climate forecast.  相似文献   

12.
ON THE PROCESS OF SUMMER MONSOON ONSET OVER EAST ASIA   总被引:6,自引:0,他引:6  
Using daily observational rainfall data covered 194 stations of China from 1961 to 1995 andNCEP model analyzed pentad precipitation data of global grid point from 1979 to 1997,thedistribution of onset date of rainy season over Asian area from spring to summer is studied in thispaper.The analyzed results show that there exist two stages of rainy season onset over East Asianregion from spring to summer rainy season onset accompanying subtropical monsoon and tropicalmonsoon respectively.The former rain belt is mainly formed by the convergence of cold air and therecurred southwesterly flow from western part of subtropical high and westerly flow from the so-called western trough of subtropical region occurring during winter to spring over South Asia.Thelatter is formed in the process of subtropical monsoon rain belt over inshore regions of South ChinaSea originally coming from south of Changjiang (Yangtze) River Basin advancing with northwardshift of subtropical high after the onset of tropical monsoon over South China Sea.The pre-floodrainy season over South China region then came into mature period and the second peak of rainfallappeared.Meiyu,the rainy season over Changjiang-Huaihe River Basin and North China thenformed consequently.The process of summer tropical monsoon onset over South China Sea in 1998is also discussed in this paper.It indicated that the monsoon during summer tropical monsoononset over South China Sea is the result of the westerly flow over middle part of South China Sea,which is from the new generated cyclone formed in north subtropical high entering into SouthChina Sea,converged with the tropical southwesterly flow recurred by the intensified cross-equatorial flow.  相似文献   

13.
Using daily observational rainfall data covered 194 stations of China from 1961 to 1995 and NCEP model analyzed pentad precipitation data of global grid point from 1979 to 1997,the distribution of onset date of rainy season over Asian area from spring to summer is studied in this paper.The analyzed results show that there exist two stages of rainy season onset over East Asian region from spring to summer rainy season onset accompanying subtropical monsoon and tropical monsoon respectively.The former rain belt is mainly formed by the convergence of cold air and the recurred southwesterly flow from western part of subtropical high and westerly flow from the so-called western trough of subtropical region occurring during winter to spring over South Asia.The latter is formed in the process of subtropical monsoon rain belt over inshore regions of South China Sea originally coming from south of Changjiang (Yangtze) River Basin advancing with northward shift of subtropical high after the onset of tropical monsoon over South China Sea.The pre-flood rainy season over South China region then came into mature period and the second peak of rainfall appeared.Meiyu,the rainy season over Changjiang-Huaihe River Basin and North China then formed consequently.The process of summer tropical monsoon onset over South China Sea in 1998 is also discussed in this paper.It indicated that the monsoon during summer tropical monsoon onset over South China Sea is the result of the westerly flow over middle part of South China Sea,which is from the new generated cyclone formed in north subtropical high entering into South China Sea,converged with the tropical southwesterly flow recurred by the intensified cross-equatorial flow.  相似文献   

14.
The relationship between the variation of precipitation in Guangdong Province is investigated using the correlation analysis and composite comparison methods in conjunction with precipitation data from 36 surface weather stations in the province and reanalyzed 850 hPa data from NCEP, U.S.A. A significant positive correlation is found between the variation of precipitation in summer there and the intensity of the southwesterly over the South China Sea though without being so inconclusive that a strong southwesterly over the sea is accompanied by more rain in Guangdong. For the front-associated flood season in April-June, the former is a carrier of rainwater for Guangdong but with insignificant linkage with the intensity of the southwest monsoon. There is even such a situation in which the precipitation gets stronger though with a weakened southwest monsoon from the tropics in May-June, which is mainly attributable to the increase of monsoon from the subtropics. For the typhoon-associated flood season in July-September, the Guangdong precipitation increases as the southwest monsoon strengthens over the central and northern South China Sea and the subtropical monsoon reduces its effects on the province.  相似文献   

15.
东亚地区夏季风爆发过程   总被引:72,自引:5,他引:67  
利用中国194站1961~1995年日降水资料及NCEP1979~1997年候格点降水资料,探讨了亚洲地区自春到夏的雨季开始分布。结果表明,东亚地区自春到夏存在副热带季风雨季开始和热带季风雨季开始。前者于4月初开始于华南北部和江南地区,随后向南和向西南扩展,于4月末扩展到华南沿海和中南半岛,这个雨带主要是冷空气和副热带高压西侧转向的SW风以及南亚地区冬春副热带南支西风槽中西风汇合而形成的,是副热带季风雨季开始。后者是南海热带季风爆发后使原来由江南移到华南沿岸的副热带季风雨带随副热带高压北进而北进,前汛期雨季进入盛期,江南出现第二次雨峰,形成梅雨期和江淮及华北雨季。同时,热带季风雨带也自东向西传播到达南亚地区而形成热带季风雨季。还讨论了1998年东亚地区夏季风爆发过程,指出南海夏季风爆发期的季风由副高北侧形成的新生气旋进入南海造成南海中部西风和南海越赤道气流转向的SW季风加强汇合而形成,因而是东亚季风系统中环流系统季节变化造成的,和印度季风无关。在南海季风爆发期阿拉伯海仍由副热带反气旋控制,南亚仍是上述副热带反气旋北侧NW风南下后转向的偏西副热带气流所控制,索马里低空急流仍未爆发,赤道西风并未影响南海。  相似文献   

16.
揭示热带气旋在湖南的降水规律可为热带气旋影响湖南的降水预报提供技术支撑。采用近67 a的热带气旋影响资料,通过统计方法,分析了影响湖南降水的热带气旋特点及环流异常特征。结果表明:7—9月是影响的高峰季节,以在广东、福建沿海登陆的热带气旋对湖南影响次数最多、程度最重,浙江、福建沿海登陆的热带气旋在湖南形成的降水范围最大,热带气旋对湖南影响所产生的降水主要集中在湖南省东南部,热带气旋对湖南产生的强降水范围有增大的趋势,降水强度有增强的趋势。福建和广东沿海登陆对湖南影响的热带气旋的环流特征为南亚高压偏强、偏东、偏北,导致西太平洋副热带高压偏强、偏西、偏北,引导副热带高压南侧的东南气流与南海和菲律宾以东洋面的西南风气流汇合,形成季风槽,中国华南和华东沿海为东南气流,有利于热带气旋在该区域登陆影响中国。只是前者表现为南亚高压位置较后者偏北更明显,西太平洋副热带高压更偏北,季风槽更偏东,导致福建登陆对湖南影响的热带气旋在湖南大部为气旋性环流控制,湖南全省降水偏多;而广东登陆对湖南影响的热带气旋在湖南省东南部为气旋性环流控制,该区域降水偏多。  相似文献   

17.
According to the basic characteristics of the activities of summer monsoon in the South China Sea,Standardized index,Is,has been designed that integrates a dynamic factor(southwesterly component) and a thermodynamic factor(OLR) for the indication of summer monsoon in the South China Sea,With the index determined for individual months of June,July and August and the entire summertime from 1975 to 1999,specific months and years are indicated that are either strong or weak in monsoon intensity,The variation is studied for the patterns and Is‘s relationship is revealed with the onset of summer monsoon and the precipitation in Guang-dong province and China.The results show that there are quasi-10 and quasi-3-4 year cycles in the interannual variation of the monsooon over the past 25 years.When it has an early(late)onset,the summer monsoon is usually strong (weak),In the strong(weak)monsoon,years,precipitation tends to be more(less)in the first raining season of the year but normal or less(normal)in the second,in the province,but it would be more(less) in northeastern China and most parts of the northern china and south of the lower reaches of the Changjiang River and less(more)in the middle and lower reaches of the river,western part of northern China and western China.  相似文献   

18.
北上热带气旋气候特征分析   总被引:3,自引:1,他引:2  
北上热带气旋是影响我国华北和东北地区的重要天气系统,其带来的大风和暴雨,常常造成我国北方地区的风灾和水灾。利用建国以来56 a的气象资料,对影响我国的北上热带气旋进行气候分析。结果表明:从时间上看,平均每年约有3个北上热带气旋,最早出现在5月下旬,最晚出现在11月中旬,其中以7月和8月为最多;每年6—9月为北上热带气旋登陆季节,7月和8月登陆的热带气旋占85%。从强度上看,能够到达北方的热带气旋一般都是较强的热带气旋,在进入北上热带气旋定义区后,总体强度明显减弱,但在进入黄渤海时仍能够达到台风的强度;与北上热带气旋相比,北上登陆热带气旋的强度更大。统计分析发现,在辽宁和华北登陆的热带气旋,其强度大于在山东半岛登陆的热带气旋。北上登陆热带气旋和北转向、中转向的热带气旋一般均能产生暴雨和大风。  相似文献   

19.
利用海陆热力差指数(ILSTD)、500 hPa位势高度场、向外长波辐射(OLR)资料及NCEP/NCAR月平均再分析数据集,分析东亚夏季风与西北太平洋地区(包括中国南海)热带气旋频数的关系,结果表明,在强夏季风年西北太平洋地区热带气旋频数偏多,而弱夏季风年同期热带气旋频数异常偏少而后期趋于正常,正常夏季风年热带气旋频数基本正常.并结合热带气旋形成的大尺度环流条件,对其动力机制作了初步探讨.  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