登陆台风研究概述

国际热带气旋研究界自20世纪90年代以来，把台风登陆从传统的台风路径体系中分离出来，成为国际台风研究的重点，例如WMO的世界天气研究计划(WWRP)、美国的天气研究计划(USWRP)和澳大利亚的某些研究项目都把台风登陆作为重点课题投入研究。陈联寿在全国第11届热带气旋科学讨论会上，提出了台风登陆的PDP计划，指出台风登陆阶段是研究台风、海洋、地形(岛屿、海岸、浅海区大陆架)3者相互作用的唯一手段。也是考察预报警报、社会响应和风暴灾害3者相互影响的良机。登陆台风引起的暴雨、台风大风、风暴潮等都有很大的变化。因此，把登陆作为一个独立的问题来研究十分必要。目前，对登陆台风研究也有不少成果，笔者从登陆台风的气候特征、陆地路径、强度变化以及登陆台风暴雨等方面作一简要的概述。     

全球气候变暖背景下登陆我国台风特征的分析

利用1949-2002年西北太平洋热带气旋、登陆我国台风和全球地面温度资料，对登陆我国台风的频数、强度以及登陆位置的年际变化，特别是趋势特征进行了分析，并与西北太平洋台风的变化特征作了对比。结果表明：在全球气候变暖背景下，我国登陆台风频数的减少趋势没有西北太平洋台风频数的减少趋势强；登陆台风的平均强度和极端强度均有减弱趋势，极端强度的减弱趋势尤为明显，但其强度弱于西北太平洋台风。在1968-2002年全球明显增暖时段，我国台风登陆位置偏向我国中部，西北太平洋台风在生命史中强度达最强时的位置有向北移动的趋势。     

1223号台风“山神”暴雨及秋冬季登陆转向台风浅析

从环流形势场、物理量场和相似个例对比分析等方面进行分析,从不同侧面研究影响南宁市的秋冬季登陆转向台风的移动路径,为该类台风可能产生的影响提前做出预报预警.结果表明:影响南宁市的秋冬季登陆转向台风的移动路径主要受副热带高压的形状、强度、中心脊线位置及与台风发展不同时期的相对位置的共同影响.     

影响河南的登陆台风分析

统计了1949～1998年从闽、浙登陆台风的气候特征及河南台风暴雨概况,并利用天气学方法对台风登陆后的移动路径进行了概括和分析,以期为这类台风的降水预报提供参考.     

登陆我国热带气旋的气候特征

利用1949～2001年西北太平洋热带气旋基本资料,对登陆我国热带气旋活动的气候特征进行了分析。结果表明,登陆我国的热带气旋频数存在显著的月际、年际和年代际差异,具有明显的时间日变化特征。同时指出,登陆我国热带气旋的频数与长江中下游地区梅雨量可能存在一定关系。此外,通过对在不同纬度带登陆的热带气旋进行统计分析发现,热带气旋所登陆的纬度带不同,其维持时间、衰减速度存在明显差异。     

影响河南的登陆台风分析

统计了1949－1998年从闽、浙登陆台风的气候特及河南省台风暴雨概况，并利用天气学方法对台风登陆后的移动路径进行了概括和分析，以期为灾类台风的降水预报提供参考。     

登陆海南岛台风季节特征的对比分析

通过对2003年盛夏(8月份)和晚秋(11月份)登陆海南岛的两个台风个例进行了大尺度环流背景、台风暴雨产生的大尺度条件、中尺度特征等方面的对比分析，揭示盛夏和晚秋登陆海南岛台风路径和暴雨的一般特性’并对其成因进行了探讨。     

我国登陆台风灾害的监测及预报技术研究--项目的意义和进展

"我国登陆台风灾害的监测及预报技术研究"(2001DIA20026)于2002年3月启动.登陆台风会直接造成社会巨灾,过去因为技术条件不够,对它的研究无法开展.如今因探测技术发展,计算机能力的提高,登陆台风已成为国际台风研究的前沿课题.世界气象组织(WMO)的全球天气研究计划(WWRP)和热带气象研究计划(TMRP)联合开展代号为ITCLP的国际登陆热带气旋研究,美国天气研究计划(USWRP)开展了代号为USLHP的登陆飓风研究,澳大利亚开展了代号为TCCIP的登陆热带气旋影响研究,我国作为台风登陆最多的国家,开展这一研究已经偏迟了10年.     

我国登陆台风引起的大风分布特征的初步分析

用1949～2001年我国台风大风实测纪录对此期间台风引起的大风进行研究,具体分析了台风引起的6级及以上、8级及以上大风的频数,和大风风速的平均值、极端最大值的分布特征,并对台风登陆的地段、季节对上述要素的影响和台风登陆前、后上述要素的变化做了进一步分析.结果表明:在引起我国境内大风天气的台风中,有62%在我国登陆;而登陆我国的台风中,有89%会引起大风过程.台风引起的我国境内大风主要出现在东南沿海,等频数线几乎与海岸线平行,向内陆急剧减小,在杭州湾以北地区较少出现8级以上的台风大风,而极端最大风速与大风频数有类似的分布;在华南登陆的台风引起的大风频数明显高于华东和华北,华东又高于华北,引起的大风风速的大值区与登陆地段较为一致;登陆台风在4～8月间逐渐增多,引起的大风范围逐步向北推进,在9～11月间登陆台风逐渐减少,大风范围逐步往南消退;台风登陆前引起的大风主要集中在沿海地带,登陆后台风大风出现范围明显扩大.     

我国沿海地区近54a台风灾害风险特征分析

台风严重影响着我国东南沿海省市的社会经济发展,本文选取南方沿海八个省市为研究区,利用1949—2002年共54 a登陆台风次数和1985—2002年的18 a经济损失的数据库信息,结合社会经济条件,对比分析了研究区台风易损性,及登陆台风的年内分布特征。探讨登陆台风的规律性及研究区台风易损性,将有利于合理部署救灾工作,合理分配救灾资源,并为社会减灾工作,尤其是长期的救灾规划提供指导作用。     

登陆台风Matsa维持机理的数值研究

使用新一代中尺度WRF模式对2005年台风Matsa(麦莎)登陆后的变化特征进行了数值模拟;对其登陆后强度持续维持的机理作了初步探讨;对登陆后涡动动能收支作了诊断分析。台风"麦莎"登陆后长久维持与以下因素密切相关。(1)持续的水汽输送通道。"麦莎"登陆后两条持续维持的水汽输送通道将暖湿空气源源不断地送入台风,为"麦莎"的维持提供了潜热能。(2)增强的高层辐散风场。200 hPa附近的辐散风场随着时间的增加而增强,所产生的"抽吸"作用和"减压"作用,对"麦莎"环流和强度的维持起到了重要的作用。(3)长久剧烈的上升运动。"麦莎"登陆后一直保持着剧烈的上升运动,强烈的上升运动把低层的暖湿空气向上输送,为"麦莎"的维持提供热能和动能。(4)活跃的中尺度扰动。"麦莎"的螺旋云带中活跃着中尺度对流系统,它们在低层所产生的较强辐合作用对"麦莎"气旋式环流的维持起到了正反馈作用。(5)涡动动能收支的诊断分析表明,"麦莎"登陆后,地形等摩擦作用和水平输送使其能量耗损,垂直通量散度项使其能量增加,平均动能与涡动动能之间的转换项是涡动动能收支中的相对小项;但随着时间的增加摩擦动能耗散作用逐渐减小,"麦莎"从中高层环境中获得了能量,涡动动能的增加从高层开始逐渐向中低层传播。     

A STUDY OF RAPID DECAY TYPHOONS IN OFFSHORE WATERS OF CHINA

On the basis of NCEP/NCAR reanalysis data and yearbooks of CMA tropical cyclones, statistical analysis is performed for 1949—2013 offshore typhoons subjected to rapid decay(RD). This analysis indicates that RD typhoons are small-probability events, making up about 2.2% of the total offshore typhoons during this period. The RD events experience a decadal variation, mostly in the 1960 s and 1970 s(maximal in the 1970 s), rapidly decrease in the 1980 s and 1990 s and quickly increase from 2000. Also, RD typhoons show remarkable seasonal differences: they arise mainly in April and July-December, with the prime stage being in October-November. The offshore RD typhoons occur mostly in the South China Sea(SCS) and to a lesser extent in the East China Sea(ECS); however, none are observed over the Huang Sea and Bo Sea.Composite analysis and dynamic diagnosis of the RD typhoon-related large-scale circulations are performed.Physical quantities of the composite analysis consist of 500-h Pa height and temperature fields, vapor transfer, vertical wind shear(VWS), density of core convection(DCC), and high-level jet and upper-air outflow of the typhoon. The results suggest that(1) at the 500-h Pa height field, the typhoon is ahead of a westerly trough and under the effects of its passing trough;(2) at the temperature field, the typhoon is ahead of a temperature trough, with an invading cold tongue present;(3) at the vapor transfer field, water transfer into the RD typhoon is cut off; and(4) at higher levels, the related jet weakens and the outbreak of convection becomes attenuated in the typhoon core. In addition, VWS bears a relation to the RD typhoon; in particular, strong VWS favors RD occurrence.The differences in RD events between the SCS and ECS show that for the RD, the VWS of the ECS environmental winds is markedly stronger in comparison with its SCS counterpart. The cold advection invading into the typhoons is more intense in the SCS than in the ECS, and the low-level vapor transfer and high-level outflow are weaker in the SCS RD typhoons.Data analysis shows that sea surface temperature(SST), VWS, and DCC can be employed as efficient factors to predict RD occurrence. With appropriate SST, VWS, and DCC, a warning of RD occurrence can be given 36, 30-36,and 30 h, respectively, in advance. These values suggest that atmospheric SST responses lag. Owing to this time lag,the prediction of RD typhoons is possible.     

TERRAIN IMPACT ON THE PRECIPITATION OF LANDFALLING TYPHOON TALIM

The impact of terrains on the precipitation of landfalling typhoon Talim (2005) over mainland China is investigated using the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model. The simulated precipitation of simulated typhoon (the control) matches the observations closely. To compare with the control simulation, four sensitivity simulations were carried out in which terrains of Wuyi Mountain, Lushan, Dabieshan, and both Lushan and Dabieshan are completely removed respectively, but other surface properties were retained. It is found that the complex terrains of Wuyi Mountain, Lushan and Dabieshan have a significant impact on the rainfall intensity and distribution of Talim. As the terrains are removed, the rainfall is decreased very greatly and the rainfall in inland area is decreased much more than that in the coastal area. Besides, the rainfall distribution near the Lushan and Dabieshan is spread much more westward compared with the control simulation. Further analysis shows that the Wuyi Mountain would increase both the lower level air convergence and the upper level air divergence for Talim that just made landfall and thus it would contribute to the convection and increase rainfall intensity. It can be concluded that the terrains of Wuyi Mountain, Lushan and Dabieshan have obvious impacts on the Talim rainfall, and their impacts are different in various landfalling periods. The present study is a useful attempt to explore the influence of orography on the TCs in mainland China.     

影响热带气旋结构和运动的两类因子的数值研究

利用一个β平面正压准地转模式，实施了４组时间积分大于５ｄ的试验。结果表明：涡度平流和β效应同样重要，它们对热带气旋的结构和移动均具有明显影响。     

我国东南海岸线分布对9216号台风暴雨增幅影响的数值研究

利用一个三重水平结构，双向嵌套的台风数值模式，以１９９２年８月２９日１２冒为初始场，根据模式中地形插值时遇到的问题，设计了实际海岩线与扩展海岸线两种方案，对９２１６号登陆台风及其暴雨进行了对比模拟试验。结果表明：地形动力抬升形成的对流陈水是台风暴雨增幅的一个重要原因。     

登陆台风近地层湍流特征观测分析

在对多个登陆台风实地观测的基础上,选取出较有代表性的实验观测个例:“黄蜂”、“杜鹃”和“黑格比”3个登陆台风,分析探讨在登陆台风的中心、靠近中心位置的强烈影响区域和台风外围环流影响地区近地层湍流特征,以期对登陆台风的边界层湍流过程有所认识。观测资料分析显示,在登陆台风的中心及其强烈影响的区域:(1)风速和湍流强度均有强烈的变化;(2)水平湍流积分尺度明显增大,越靠近中心位置,增大越明显,而垂直方向没有明显变化;(3)在湍流谱的低频和高频区,湍能均可增大1~2个量级,其中垂直方向湍能增大的幅度略小于水平方向;(4)湍谱在惯性子区u,v,w3个方向的分布均不满足-5/3次方律,存在较大偏移,而在台风外围环流影响区和无台风影响时,则无上述的4个特征。     

登陆台风对陕西一次强雷暴天气的作用

利用常规的天气图和物理量资料对1994年8月5～6日发生在陕西中部的一次区域性大风、冰雹、强暴雨天气进行诊断分析，结果表明：登陆台风的北上使得副热带高压东退，导致西风槽向东移动，带来弱冷空气，触发了陕西中部不稳定能量的释放。登陆台风向暴雨区输送了大量的能量和水汽。850hPa偏东急流左前侧的辐合区与200hPa西南急流入口区右侧辐散区重叠，产生的急流次级环流为强雷暴提供了持续强劲的上升运动。     

AN OBSERVATIONAL STUDY ON DISTRIBUTION OF PRECIPITATION ASSOCIATED WITH LANDFALLING TROPICAL CYCLONES AFFECTING CHINA

In order to provide an operational reference for tropical cyclone precipitation forecast,this study investigates the spatial distributions of precipitation associated with landfalling tropical cyclones(TCs) affecting China using Geostationary Meteorological Satellite 5(GMS5)-TBB dataset.All named TCs formed over the western North Pacific that made direct landfall over China during the period 2001-2009 are included in this study.Based on the GMS5-TBB data,this paper reveals that in general there are four types of distribution of precipitation related to landfalling TCs affecting China.(a) the South-West Type in which there is a precipitation maximum to the southwestern quadrant of TC;(b) the Symmetrical South Type in which the rainfall is more pronounced to the south side of TC in the inner core while there is a symmetrical rainfall distribution in the outer band region;(c) the South Type,in which the rainfall maxima is more pronounced to the south of TC;and(d) the North Type,in which the rainfall maxima is more pronounced to the north of TC.Analyses of the relationship between precipitation distributions and intensity of landfalling TCs show that for intensifying TCs,both the maximum and the coverage area of the precipitation in TCs increase with the increase of TC intensity over northern Jiangsu province and southern Taiwan Strait,while decreasing over Beibu Gulf and the sea area of Changjiang River estuary.For all TCs,the center of the torrential rain in TC shifts toward the TC center as the intensity of TC increases.This finding is consistent with many previous studies.The possible influences of storm motion and vertical wind shear on the observed precipitation asymmetries are also examined.Results show that the environmental vertical wind shear is an important factor contributing to the large downshear rainfall asymmetry,especially when a TC makes landfall on the south and east China coasts.These results are also consistent with previous observational and numerical studies.     

登陆台风远距离暴雨的观测研究和预报

对１９８７￣１９９２年在汕头以北登陆的全部台风个例分析表明：登陆台风陆上活动类型和远距离暴雨特点与台风在近海的活动方式有关；登陆台风远距离暴雨的发生与台风登陆前后大气低层东南气流里是否存在中尺度暖区有关，落区与中尺度暖区在台风、副高系统中的相对位置有关，最后，建立了台风远距离暴雨预报的天气学模式。