登陆华东热带气旋的气候特征分析

利用1949—2006年西北太平洋及南海的热带气旋（TC）资料,分析了登陆我国的TC强度、登陆时间、登陆后路径趋向及强度变化等气候特征,并重点讨论了直接登陆华东和登陆台湾后再次登陆华东的TC路径和强度趋势差异。结果表明,直接登陆华东的TC比登陆台湾后再次登陆华东（以下简称为间接登陆）的TC更易北上或北上转向,而间接登陆的TC更易维持西偏北行;另外直接登陆华东的TC登陆后的强度更易维持,其登陆后路径趋向在西北偏西和西南方位的强度明显减弱的百分比率比其它方位的大。      

ENSO事件影响下登陆中国热带气旋年际变化特征的分位数回归分析

热带气旋每年对我国东南沿海地区造成很大的经济损失和人员伤亡。为了解登陆中国热带气旋的强度、位置和生成频率等特征,基于1949—2018年西北太平洋热带气旋数据,采用分位数回归的方法分析了登陆中国热带气旋活动年际变化特征规律。结果发现:登陆中国热带气旋活动年际变化特征受ENSO事件的影响,El Ni?o年、La Ni?a年和正常年登陆中国热带气旋的最大风速、最长生命期和生成位置的年际变化规律存在较大差异,且这种差异程度和热带气旋强度有关;此外,在不同的分位数下登陆中国热带气旋活动特征的年际变化趋势系数并不相同。研究结果可以为我国的东南沿海热带气旋数据分析和趋势预测提供有效的参考。      

登陆广东省热带气旋的奇异谱分析

利用奇异谱方法(SSA方法)分析登陆广东省的热带气旋的演变规律，发现年登陆的热带气旋数存在明显的8年、准3年的周期振荡；登陆珠江口以西的热带气旋数存在12年、准2年的周期振荡。把产生热带气旋的源地——西北太平洋划分为8个海区，对每个海区的海表温度进行奇异谱分析，结果显示NIN0西区和暖池海区分别存在8年和3年的准周期振荡及12年和2年的周期振荡，这很可能是登陆广东的热带气旋产生的物理原因。最后结合最大炳谱方法(SSA—MEM)做出登陆广东省的全年和登陆珠江口以西的热带气旋趋势预报，其效果较理想，在短期气候预测业务中有一定的参考价值。     

热带气旋影响下深圳地区闪电特征研究

研究热带气旋影响下广东省深圳地区的闪电特征及规律。利用2012—2019年西北太平洋热带气旋历史数据,筛选出2012—2019年距离深圳市国家气象基本站1 000 km内的热带气旋,按热带气旋强度等级进行分组。并利用同时期深圳地区闪电、温度观测数据,研究不同等级热带气旋在不同距离、方位角情况下,深圳地区的闪电特征。发现热带气旋影响下深圳地区闪电年际差异很大,一年中7月和8月深圳地区闪电活动最活跃。热带气旋对深圳地区闪电活动影响大的距离大多为400 km以外,即深圳处于热带气旋的外围雨带。总体上在台风季,TD、TS、STS较易引发深圳地区的闪电,尤其是当TS位于福建地区,距离深圳400～600 km时,极易给深圳地区带来闪电影响。研究结果可为深圳地区的防台减灾工作提供科技参考。     

影响我国热带气旋活动的气候特征及其与太平洋海温的关系

利用1956~2000年的热带气旋(简称TC,下同)资料对影响我国TC活动的气候特征进行了初步的统计分析,结果发现影响我国的TC活动具有明显的阶段性特征,1960年代影响我国的TC数明显偏少,而后进入偏多期,1990年代又相对偏少。影响我国的TC强度多集中于980~999 hPa,华东的闽、浙一带TC登陆比华南晚,但强度较大。在此基础上通过对影响我国的TC年个数与太平洋海温场进行相关分析,发现两个相关较密切的区域: 西太平洋暖池(120~150 E, 10~20 N)正相关区、赤道中东太平洋(180 ~90 W, 10 S~5 N)负相关区,这两个相关区具有较好的持续性。进一步分析影响我国的TC在El Ni駉年与La Ni馻年的气候特征发现,El Ni駉年影响我国的TC数较少,但强度较大,La Ni馻年则相反,影响我国TC多年和少年对应的太平洋海温距平分布形势分别与La Nia年和El Nio年的海温距平分布形势类似。     

登陆我国过湖泊热带气旋的统计特征

利用1949～2001年热带气旋年鉴资料,对53年登陆我国并经过内陆湖泊的热带气旋特征进行统计分析.结果表明:登陆过湖泊热带气旋在陆上维持时间长,登陆时强度较强;湖泊地带能延缓登陆TC强度的衰减;热带气旋经过内陆湖泊时大多表现为中心气压维持不变或降低,风速增大;长江中游地区是登陆过湖泊热带气旋消失数最多的区域.     

华南地区热带气旋登陆前强度突变的大尺度环境诊断分析

利用每6小时一次的NCEP再分析资料,对华南地区登陆前突然减弱和突然增强的两类热带气旋（TC）进行大尺度诊断分析,结果表明：（1）突然增强的TC位于副高的西南侧或南侧,低空有明显的西南气流卷入TC内部,而突然减弱的TC基本在副高西侧或西北侧;（2）突然增强TC的低空辐合、高空辐散均较强;（3）充足的水汽输送是TC登陆前突然增强的另一重要原因。     

登陆粤西的热带气旋降水特征分析

利用1949～2000年《热带气旋年鉴》资料,对51年来登陆粤西的热带气旋在陆地维持时间、不同强度的降水之间的分布、相同量级强降水的分布等进行统计分析,揭示登陆粤西热带气旋降水分布实况和特征。结果表明,登陆粤西的热带气旋在登陆后的维持时间和其造成陆地强降水范围成正相关的关系;热带气旋造成不同强度(暴雨、大暴雨、特大暴雨)的降水在其路径左右侧分布,雨强越大,出现的几率越少;热带气旋登陆后造成的暴雨量级降水在热带气旋路径右侧比左侧产生的几率更大;而大暴雨、特大暴雨落在路径左侧的可能性比落在右侧的可能性大。     

近海北上热带气旋特征及对华东沿海地区影响分析

使用常规观测、FY2C卫星云图、CIMSS气象卫星云图分析、2000—2012年台风路径、NCEP再分析等资料,统计了2000年以来近海北上的热带气旋(下面统称为NTC)对华东沿海地区的风雨影响,分析了NTC的路径、强度、结构等特征,以及与华东沿海地区的风雨的关系。结果表明NTC对华东沿海地区是否有较严重风雨影响,取决于其北上路径与沿海地区距离的远近、NTC的强度和范围大小。当NTC中心距离陆地300 km,在124.5°E以西北上对华东沿海地区有较严重风雨影响,如果NTC强度在台风等级以上时会对上海产生较严重风雨影响。在125°E以东北上的NTC,强度在台风等级以下时对华东沿海地区影响较小。NTC在东海近海北上时,强台风、超强台风的强度是逐渐减弱的;较弱的台风或强热带风暴及热带风暴强度将维持或略有加强。NTC在东海近海北上时,当离沿海地区距离300 km时,结构易变得非对称。强度强和范围大的NTC结构也易变得非对称。NTC结构变得非对称后其强度将进一步减弱。随着NTC北上海温逐渐降低,在NTC西部靠近陆地其水汽条件比东部差,NTC结构会变得不对称,NTC北上到较高纬度风的垂直切变一般会变大,NTC脱离赤道辐合带后其水汽输送条件变差等等都会使较强的NTC北上后减弱。另外,NTC与所处的高低空环境相互作用也会影响其强度变化。     

影响福建热带气旋活动特征分析

分析了1960—2005年影响福建热带气旋(简称TC)的活动特征，结果表明：影响TC频数呈减少趋势；7—9月影响频数多，8月为最多；影响频次的空间分布呈东南-西北递减的带状分布；南海是影响TC生成频数最多的集中区域。分析了TC异常活动的环境场，在TC异常偏多年份，低层ITCZ位置偏北，西北太平洋(WNP)生成TC位置也较偏北，同时在中国东南沿海为异常的气旋性距平环流控制，非常有利于TC的生成和发展。对于低压环流影响年份，在WNP区域TC生成频数偏多偏北情况下影响中国东南沿海地区TC较频繁，则影响福建TC数偏多；反之，ITCZ明显偏弱，中国东南沿海为异常的反气旋性距平环流控制时，影响福建TC数偏少。对亚洲地区500 hPa大气环流分析发现，影响福建TC异常偏多(少)年份，副热带高压位置偏北(南)。     

ANALYSIS ON THE CHARACTERISTICS OF TROPICAL CYCLONES MAKING LANDFALL ON DIFFERENT REGIONS OF CHINESE MAINLAND

The locations(longitudes and latitudes)of the tropical cyclones(TCs)making landfall on the Chinese mainland from 1949 to 2008 are investigated in detail by using ArcGis and FORTRAN routine.The southeast coastline[110 to 122°E)with most landfall TCs was selected as the key region,which was divided into 12 subsections with 1°intervals of longitude.The study period was from July to September in each year.The result showed that the average sustaining time of TCs making landfall on the subsections east of 118°E is longer than those west of 118°E.Before landfall,the averaged TC intensity in the subsections east of118°E is stronger than that west of it.After landfall,however,the difference between the west and east is not significant.The index of destructive potential for the period before/after landfall was defined as TDP1/TDP2.The maximum of TDP1/TDP2 occurred in the subsection of[119,120°E)/[110,111°E).The ENSO impact on the frequency and average location of landfall TC over the whole region at 110 to 122°E is not obvious,but the effect varies with specific subsections.There is little differences of averaged TDP1 in the subsections between different phases of ENSO events,but the averaged TDP2 is larger in the warm events than that in the cold events.The rainstorm days of each station caused by TCs in different subsections were counted respectively.The results suggested that the rainstorm days of the subsections east of 118°E are much more than those west of 118°E.The larger values are primarily distributed at the subsections of[119,120°E)and[110,111°E).     

登陆中国不同强度热带气旋的变化特征

根据《热带气旋等级》国家标准(2006),将热带气旋(TC)划分为热带低压(TD)、热带风暴(TS)、强热带风暴(STS)、台风(TY)、强台风(STY)、超强台风(SSTY)6个等级,利用中国气象局整编的1949—2006年共58年的《台风年鉴》和《热带气旋年鉴》资料,分析了登陆中国大陆、海南和台湾不同强度TC变化特征。结果表明：(1) 不同强度登陆TC频数存在年际和年代际变化,在长期趋势上,TD、TS登陆频数呈现显著的线性递减趋势,STY登陆频数呈现显著增加趋势。(2) 登陆TD、TS、STS存在6—8年的周期变化,TY具有准16年的周期变化。(3) 登陆TD、TS主要生成于南海东北部海面,登陆TY、STY、SSTY多生成于巴士海峡东南部海面和菲律宾以东洋面。(4) 在年代际变化上,南海生成的登陆TD、TS频数有减少趋势,TY、STY有增多趋势。     

2008年西北太平洋热带气旋活动异常特征及成因分析

2008年西北太平洋热带气旋活动的特点:(1)初台异常偏早;(2)生成热带气旋异常偏少,但登陆热带气旋异常偏多,登陆热带气旋与生成热带气旋比例高;(3)从热带气旋的生成源地来看,2008年的热带气旋生成位置明显偏西.2008年热带气旋生成年频数异常偏少的主要原因:2008年仍处在生成热带气旋偏少的气候背景下,对流层低层...     

ANALYSIS OF CAUSATION OF ABNORMAL MOTION OF LANDING TROPICAL CYCLONES IN GUANGDONG

1 INTRODUCTION It is doubtless that TCs making landfalls on Guangdong are one of the important aspects of the research on and prediction of short-term climate changes for the province. With regard to the climate patterns of TCs motion and factors governin…     

中国东部冷、热夏与近海强热带气旋变化的若干特征

利用１９５１－１９９４年台风鉴和气温资料，在划分冷、热夏标准的基础上，分别统计分析了我国东部近海强热带气旋活动的某些特征。结果发现，我国东部冷夏年近海强热带气旋无论在其频数，路径，强度和移速变化等均与热夏年迥然不同。讨论了这种差异的环流背景特征。     

FACTORS AFFECTING THE TRACK OF TROPICAL CYCLONES AFTER LANDFALL IN EASTERN CHINA

The correlation and composite analysis are carried out in this paper to study major factors affecting the track of tropical cyclones (TCs) after their landfall in the east of China. The mid-tropospheric environmental steering flow is found to dominate the movement of a TC even after landfall, with the inertia and Coriolis force two other subordinates. A key region is discovered covering the east of China and Yellow Sea, in which the environmental flow significantly affects the movement of TCs making landfall in this part of China. When the subtropical high in this region strengthens and extends westward, accompanied by northward shrink of the westerly trough, the TC tends to move westward after landfall and disappear inland. However, when the subtropical high in this region weakens and shrinks eastward, accompanied by southward push of the westerly trough, the TC tends to recurve after landfall and re-enter the sea at a location to the north of the site of landfall. The environment before the landfall of a TC has little impact on its post-landfall track, which is sensitive to the environmental change 12 – 24 hours after landfall. A 6-hour lag is found between the environmental change and the movement of a TC after landfall.     

对东海热带气旋登陆后路径趋势的若干探讨

应用相关分析与合成分析方法分析了影响东海热带气旋登陆后路径趋势的若干因素,结果表明：登陆后路径趋势随时间和登陆地点的变化分布说明热带气旋登陆后路径仍受基本气流的引导和制约;热带气旋登陆时的惯性和地转力的变化对东海热带气旋登陆后的路径趋势有一定影响;环境场及其变化对东海热带气旋登陆后路径有较大影响,尤其对流层中层流场对登陆后的热带气旋的移动仍有明显的引导作用;中国东部至黄海区域是环境场影响东海热带气旋登陆路径趋势的关键区,当区域内的西北太平洋副热带高压加强西伸,西风槽北撤时,东海热带气旋登陆后在副高南侧东风气流引导下向内陆西行至消亡,当区域内副高减弱东退,西风槽南压时,东海热带气旋登陆后受副高西侧偏南气流与西风槽前西南气流引导转向后入海;东海热带气旋登陆前的环境场对登陆后路径趋势影响相对较小,登陆后12～24小时是登陆后路径趋势受环境场影响的敏感时段,环境场的变化对登陆后路径趋势的影响要比当前环境场的影响超前6小时。     

COMPARISONS OF THE CHARACTERISTICS OF TROPICAL CYCLONES EXPERIENCING EXTRATROPICAL TRANSITION IN THE WESTERN NORTH PACIFIC BASED ON DIFFERENT DATASETS

The differences in the climatology of extratropical transition(ET) of western North Pacific tropical cyclones(TCs) were investigated in this study using the TCs best-track datasets of China Meteorological Administration(CMA),Japan Meteorological Agency(JMA) and the Joint Typhoon Warning Center(JTWC). The results show that the ET identification, ET completion time, and post-ET duration reported in the JTWC dataset are greatly different from those in CMA and JMA datasets during 2004-2010. However, the key differences between the CMA and JMA datasets from 1951 to 2010 are the ET identification and the post-ET duration, because of inconsistent objective ET criteria used in the centers. Further analysis indicates that annual ET percentage of CMA was lower than that of JMA, and exhibited an interannual decreasing trend, while that of JMA was an unchanged trend. The western North Pacific ET events occurred mainly during the period June to November. The latitude of ET occurrence shifted northward from February to August,followed by a southward shift. Most of ET events were observed between 35°N and 45°N. From a regional perspective,TCs tended to undergo ET in Japan and the ocean east to it. It is found that TCs which experienced the ET process at higher latitudes were generally more intense at the ET completion time. TCs completing the ET overland or offshore were weaker than those finishing the ET over the ocean. Most of the TCs weakened 24 h before the completion of ET.In contrast, 21%(27%) of the TCs showed an intensification process based on the CMA(JMA) dataset during the post-ET period. The results presented in this study indicate that consistent ET determination criteria are needed to reduce the uncertainty involved in ET identification among the centers.     

NUMERICAL ANALYSIS ON THE ROLE OF TROPICAL STORM NAMTHEUN IN THE UNUSUAL TRACKS OF THREE TROPICAL CYCLONES IN 2010

Tropical cyclones (TCs) Lionrock, Kompasu, and Namtheun were formed successively within 40 hours in 2010. Over the next several days afterwards, these TCs exhibited unusual movements which made operational prediction difficult. Verifications are performed on the forecasts of the tracks of these TCs with six operational models, including three global and three regional models. Results showed that the trends of TC tracks could be reproduced by these models, whereas trajectory turning points and landfall locations were not simulated effectively. The special track of Lionrock should be associated with its direct interaction with Namtheun, according to a conceptual model of binary TC interaction. By contrast, the relation between Kompasu and Namtheun satisfied the criteria for a semi-direct interaction. Numerical experiments based on the Global and Regional Assimilation and Prediction System-Tropical Cyclone forecast Model (GRAPES-TCM) further confirmed the effect of Namtheun on the unusual tracks of Lionrock and Kompasu. Finally, the physical mechanism of binary TC interaction was preliminarily proposed.     

STATISTICAL CHARACTERISTICS ON TROPICAL CYCLONES LANDFALL IN CHINA

With the data from the Tropical Cyclone Yearbooks between 1970 and 2001, statistical analyses were performed to study the climatic features of landfall TCs (noted as TCs hereafter) in China with particular attention focused on landfall frequency, locations, sustaining, decaying, transition, intensification and dissipation etc. The results indicate that the sustaining periods of TC over land are quite different for different landfall spots, and increased from Guangxi to Zhejiang. The most obvious decreasing of TC intensity occurs mainly within 12 hours after landfall. The stronger a TC is,the more it decays. The areas over which TCs are dissipated can be in Heilongjiang, the northernmost, and Yunnan, the westernmost. Besides, Guangxi is an area with high dissipating rate and subject to TC dissipation as compared with the other coastal regions.