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1.
Thermodynamic Characteristics of Tropical Cyclones with Rapid Intensity Change over the Coastal Waters of China 
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下载免费PDF全文 In order to investigate the different thermodynamic mechanisms between rapid intensifying (RI) and rapid weakening (RW) tropical
cyclones (TCs), the thermodynamic structures of two sets of composite TCs are analyzed based on the complete-form vertical
vorticity tendency equation and the NCEP/NCAR reanalysis data. Each composite is composed of five TCs, whose intensities change
rapidly over the coastal waters of China. The results show that the maximum apparent heating source Q
1 exists in both the upper and lower troposphere near the RI TC center, and Q
1 gets stronger at the lower level during the TC intensification period. But for the RW TC, the maximum Q
1 exists at the middle level near the TC center, and Q
1 gets weaker while the TC weakens. The maximum apparent moisture sink Q
2 lies in the mid troposphere. Q
2 becomes stronger and its peak-value height rises while TC intensifies, and vice versa. The increase of diabatic heating with
height near the TC center in the mid-upper troposphere and the increase of vertical inhomogeneous heating near the TC center
in the lower troposphere are both favorable to the TCs’ rapid intensification; otherwise, the intensity of the TC decreases
rapidly. 相似文献
2.
中国近海热带气旋强度突变的热力特征 总被引：2，自引：0，他引：2
应用2000 2006年的NCEP/NCAR再分析资料,通过合成分析和对比分析,利用全型垂直涡度倾向方程,研究中国近海热带气旋强度突变的热力特征.结果表明:(1)突然增强热带气旋在其中心附近对流层高低层均存在视热源Q1的极大值中心,低层Q1在突然增强过程中越来越强;而突然减弱热带气旋在中心附近对流层中层存在Q1的极大值中心,而且在突然减弱过程中Q1越来越弱.视水汽汇Q2的极值中心在热带气旋强度变化过程中位于对流层中层,在突然增强过程中有所增大,而在突然减弱过程中有所减小.(2)Q1的峰值高度在热带气旋突然增强和突然减弱过程中分别位于对流层高层和中层.Q2的峰值高度在热带气旋突然增强过程中不断抬升,而在突然减弱过程中不断降低,这说明积云对流的垂直输送在热带气旋突然增强过程中起到一定作用.(3)热带气旋中心附近对流层中上层非绝热加热随着高度增加、对流层低层垂直非均匀加热的增大有利于热带气旋的突然增强,反之导致热带气旋突然减弱. 相似文献
3.
西北太平洋热带气旋强度变化的若干特征 总被引：2，自引：0，他引：2
使用NOAA海表温度资料、ECMWF再分析资料和JTWC台风最佳路径数据,对1984—2013年30年西北太平洋热带区域（100 °E~180 °,0~60 °N）内热带气旋（TC）的强度变化特征及其与环境风垂直切变（VWS）、海表温度（SST）、最大风速半径（RMW）的关系作了统计分析,尤其关注TC强度突变。结果表明:（1）在研究区域内,TC样本中35.2%强度稳定,52.8%强度变化缓慢,仅12.0%强度突变,约92.7%的迅速加强TC样本发生在其台风及以上强度等级;（2）2000年以来,TC强度稳定样本减少,强度迅速变化样本增多。5月和9—10月是TC强度突变的高频期;（3）超过12 m/s的环境VWS下TC迅速加强较少,且只有台风及以上强度TC才能在大于12 m/s的VWS下迅速加强;（4）TC加强和迅速加强主要在28.5~30.0 ℃的SST洋面上发生,在较低SST下仍迅速加强的TC强度等级较高;（5）TC样本的RMW多小于100 km,其中强度突变TC RMW峰值区在20~40 km;（6）加强TC的RMW的24 h变化一般减小,减弱TC的RMW则增大;其中强度突变TC尤其明显,超强台风发生迅速加强时,RMW减小的比率达84.6%,但仍有15.4%比率的RMW增大。 相似文献
4.
利用2000—2014年热带气旋(TC)最佳路径、最终分析资料和静止卫星红外云顶亮温(TBB)资料,对比分析了西北太平洋(WNP),以及南海(SCS)的迅速加强(RI),与非迅速加强(non-RI)TC样本的环境背景和TBB统计特征,其中non-RI样本细分为不同的强度变化率即:缓慢加强(SI),强度稳定、缓慢减弱和迅速减弱等。结果表明,相对于SI,WNP海域的RI样本处于海表温度较高、海洋上层热容量较大、最大可能强度较大、高层辐散较强、风垂直切变(VWS)较弱和高层纬向风(U200)偏东分量较大等环境背景条件下;SCS海域的RI样本较易发生在VWS较弱的环境背景条件下。此外,相对于non-RI,支持RI发展的有利条件还包括中低层相对湿度较大、高层环境温度较低等。RI样本通常具备的TBB特征为TC内核的对流云覆盖率较大、TBB平均值相对较小。采用K最近邻分类算法进行RI预报试验,交叉检验结果表明,该方法对RI样本有一定的识别预报能力,RI样本概括率达到74.2%,技巧评分达到0.717。 相似文献
5.
利用2005~2014年全球闪电定位网（WWLLN）资料和中国气象局提供的热带气旋（Tropical Cyclone,TC）位置和强度资料,分析了近10年西北太平洋地区228个TC中的闪电时空分布特征及其与气旋强度变化的关系。结果表明:TC闪电活动年际变化呈震荡分布,夏半年闪电活动比冬半年强,闪电频数日变化呈单峰分布,峰值出现在12:00（地方时,下同）,谷值出现在06:00。闪电密度呈三圈分布结构,内核区和外雨带区闪电密度较高,内雨带区最低;闪电密度空间不对称分布,最高值出现在TC南侧。TC强度改变时,内核区闪电密度随TC不同强度等级的分布与外雨带区不同。TC内核区闪电活动较外雨带区强,内核区和外雨带区的闪电密度最大值分别出现在TC快速增强和强度一般变化时;快速增强过程一般发生在中等强度的TC中,而快速减弱过程一般发生在强度较强的TC中。TC快速增强前后,内核区闪电活动变化比全部TC闪电和外雨带区明显,表明内核闪电活动较全部TC闪电和外雨带区闪电能更好的指示TC的快速增强。 相似文献
6.
西北太平洋热带气旋快速增强阶段的风速分布特征 总被引：1，自引：2，他引：1
利用联合台风预警中心的最优路径（best-track）资料,筛选出西北太平洋地区快速增强和非快速增强两类热带气旋样本。利用美国国家海洋与大气管理局（NOAA）的多平台热带气旋表面风分析资料,对比分析了两类样本的风速和涡度的分布特征。结果显示,快速增强的热带气旋样本通常结构更紧凑,最大风速较大,最大风速半径较小,台风内区的风速较大。在涡度上表现为快速增强热带气旋样本内区的涡度和涡度梯度较大。对两类样本进行t检验,结果显示两类样本内区的切向风差异明显,说明热带气旋的内区风速分布与其发展之间存在密切联系。其物理机制可能是:当存在较大的内区涡度梯度时,涡度隔离机制有利于对流单体向涡旋中心汇聚,此外较大的涡度意味着较大的惯性稳定度,有利于非绝热加热向热带气旋动能的转换,二者共同作用有利于热带气旋的快速发展。 相似文献
7.
Two different initialization schemes for tropical cyclone(TC) prediction in numerical models are evaluated based on a case study of Typhoon Lekima(2019). The first is a dynamical initialization(DI) scheme where the axisymmetric TC vortex in the initial conditions is spun up through the 6-h cycle runs before the initial forecast time. The second scheme is a bogussing scheme where the analysis TC vortex is replaced by a synthetic Rankine vortex. Results show that although both initialization schemes can help improve the simulated rapid intensification(RI) of Lekima, the simulation employing the DI scheme(DIS) reproduces better the RI onset and intensification rate than that employing the bogussing scheme(BOG).Further analyses show the cycle runs of DI help establish a realistic TC structure with stronger secondary circulation than those in the control run and BOG, leading to fast vortex spinup and contraction of the radius of maximum wind(RMW).The resultant strong inner-core primary circulation favors precession of the midlevel vortex under the moderate vertical wind shear(VWS) and thus helps vortex alignment, contributing to an earlier RI onset. Afterwards, the decreased vertical shear and the stronger convection inside the RMW support the persistent RI of Lekima in DIS. In contrast, the reduced VWS is not well captured and the inner-core convection is weaker and resides farther away from the TC center in BOG,leading to slower intensification. The results imply that the DI effectively improves the prediction of the inner-core process,which is crucial to the RI forecast. 相似文献
8.
Atmospheric Infrared Sounder (AIRS) temperature profiles during the period 2003–2013 are used to examine the warm core structures and evolution characteristics associated with the formation and development of western North Pacific (WNP) tropical cyclones (TCs). The warm core with a steady 1.5-K warming in the layer of 500–300 hPa occurs 24 h prior to tropical storm formation. Apparent eye warming extends upward to upper troposphere and downward to near surface after tropical storm formation. TC intensity shows a robust positive correlation with the warm core strength and has a weaker but still significant positive correlation with the warm core height (the weaker correlation is primarily attributed to the scattered warm core heights of weak TCs). Future 24-h intensity change of TCs has little correlation with the warm core height while it has a significant negative correlation with the warm core strength. Weak to moderate warm core at 500–200 hPa may be a necessary but not sufficient initial condition for TC rapid intensification. AIRS-observed warm core structures, in combination with other environmental factors, have the potential to improve the prediction of tropical storm formation and rapid intensification of WNP TCs. 相似文献
9.
基于风廓线雷达的广东登陆台风边界层高度特征研究 总被引：3，自引：1，他引：2
针对8个登陆广东省的热带气旋,利用经过数据质量控制的风廓线雷达连续、高时空分辨率的风场观测数据,对热带气旋边界层特征进行了分析。研究结果表明:热带气旋边界层中切向风速大值区垂直范围越大、风速越强、持续时间越久,则热带气旋强度越大、登陆后强度维持时间越久。眼区外入流层厚度越大,入流层气流越强,热带气旋登陆后强度维持时间则越久。风廓线雷达信噪比垂直梯度对大气湍流信息有一定的指示作用,对于入流层高度在2000 m以下的热带气旋,其入流层顶所在高度与信噪比梯度最大值所在高度相近,对于入流层较为深厚的热带气旋,用信噪比垂直梯度确定的边界层高度虽接近入流层顶高,但仍有一定差距。不同特点的热带气旋其边界层高度并不相同,对于登陆后强度迅速减弱的热带气旋边界层高度在500~1000 m;登陆后强度持续时间短的热带气旋,其边界层高度约1000~2000 m;登陆后强度持续时间长的热带气旋,其边界层高度在2000 m之上,最高可达5000~7000 m。这些结果加深了对登陆台风边界层高度演变特征的认识。 相似文献
10.
Based on observed rainfall data, this study makes a composite analysis of rainfall asymmetry in tropical cyclones(TCs) after making landfall in Guangdong province(GD) during 1998—2015. There are 3.0 TCs per year on average making landfall in GD and west of GD(WGD) has the most landfall TCs. Most of TCs make landfall in June,July, August, and September at the intensities of TY, STS, and TS. On average, there is more rainfall in the southwest quadrant of TC in CGD(center of GD), WGD, and GD as a whole, and the maximum rainfall is located in the southwest near the TC center. The mean TC rainfall in the east of GD(EGD) leans to the eastern side of TC. The TC rainfall distributions in June, July, August, and September all lean to the southwest quadrant and the maximum rainfall is located in the southwest near the TC center. The same features are found in the mean rainfall of TD, TS, STS, TY,and STY. The maximum rainfall is mainly in the downshear of vertical wind shear. Vertical wind shear is probably the dominate factor that determines asymmetric rainfall distribution of TCs in GD. Storm motion has little connection with TC rainfall asymmetry in GD. 相似文献
11.
利用TMI反演的水汽凝结物对热带气旋潜热结构分布的探索研究 总被引：3，自引：0，他引：3
本文利用热带测雨卫星TRMM（Tropical Rainfall Measuring Mission）微波成像仪TMI（TRMM Microwave Imager）2A12 水汽凝结物（Hydrometeor）反演资料,对西北太平洋地区从1998～2009 年的236 个热带气旋个例的1776 个“快照”（snapshot）的水汽凝结物的结构特征进行了分析,并探讨了水汽凝结物的时空变化与热带气旋强度演变联系。研究结果表明:（1）TMI 2A12 水汽凝结物资料显示出了热带气旋内部的细致结构及变化特征,水汽凝结物的峰值集中于数十公里到一百多公里的热带气旋眼壁及云墙区;在热带气旋发展过程中,随着热带气旋强度的增强,水汽凝结物增多且往其中心靠拢,从发展阶段到成熟阶段,水汽凝结物的大值中心基本上集中在距离热带气旋中心约50 km 区域,而且强度越强的热带气旋,水汽凝结物的大值中心与热带气旋中心的距离越近;在热带气旋消亡的过程中,水汽凝结物不断减弱且往外围扩散,逐渐扩展到远离中心的区域;（2）热带气旋强度与水汽凝结物的分布关系密切,热带气旋强度变化与热带气旋中心附近200 km 范围内的水汽凝结物含量存在显著的正相关,而200 km 以外的外围水汽凝结物含量存在负相关;（3）热带气旋强度变化与水汽凝结物的变化存在时间差,水汽凝结物的变化超前于热带气旋强度的变化,在热带气旋迅速发展之前数小时,热带气旋中心0～50 km 环状区域的水汽凝结物含量就已经提前增加了,在热带气旋减弱前数小时到十数小时,即使热带气旋还处于它强度的鼎盛时期,其中心0～50 km 环状区域的水汽凝结物含量就已经提前显著减少了,这种水汽凝结物的变化超前于热带气旋强度的变化的现象,可能是热带气旋强度预报的潜在线索。 相似文献
12.
This study examines the long-term change in the threat of landfalling tropical cyclones(TCs) in East Asia over the period 1975–2020 with a focus on rapidly intensifying(RI) TCs. The increase in the annual number of RI-TCs over the western North Pacific and the northwestward shift of their genesis location lead to an increasing trend in the annual number of landfalling RI-TCs along the coast of East Asia. The annual power dissipation index(PDI), a measure of the destructive potential of RI-TCs at landfall, also shows a significant increasing trend due to increases in the annual frequency and mean landfall intensity of landfalling RI-TCs. The increase in mean landfall intensity is related to a higher lifetime maximum intensity(LMI) and the LMI location of the landfalling RI-TCs being closer to the coast. The increase in the annual PDI of East Asia is mainly associated with landfalling TCs in the southern(the Philippines, South China, and Vietnam) and northern parts(Japan and the Korean Peninsula) of East Asia due to long-term changes in vertical wind shear and TC heat potential. The former leads to a northwestward shift of favorable environments for TC genesis and intensification, resulting in the northwestward shift in the genesis, RI, and LMI locations of RI-TCs. The latter provides more heat energy from the ocean for TC intensification, increasing its chances to undergo RI. 相似文献
13.
西北太平洋不同路径下热带气旋快速加强统计特征及影响因子分析 总被引：5，自引：5，他引：0
利用2002—2011年JTWC最佳路径资料和NCEP的1°×1°全球最终分析资料以及热带气旋年鉴,分析了西北太平洋不同路径下热带气旋(TC)快速加强(RI)的时空分布特征,并对不同路径下快速加强(RITC)和缓慢加强(Non-RITC)两组TC进行合成分析和对比分析。结果表明:转向路径发生RI频率最大,且转向路径中西转向的TC最易发生RI过程;其次是东北和西北行路径。在时间分布上,各个路径下RI的月际和日变化具有不同的位相分布特征;在空间分布上,大多数RI过程发生在菲律宾和台湾岛以东洋面,西行路径在南海北部也出现较多RI过程,转向路径RI过程多发生在转向处。各个路径下RITC与Non-RITC环境场存在较明显差异,RITC对流层上层的南亚高压相对较弱,中低层副高相对较强,对流层低层存在较大的相对湿度,且湿度大值区域位于TC移动方向前侧。不同路径下的快速加强的环境影响因素也有所不同。 相似文献
14.
本文利用非静力平衡的中尺度模式MM5(V3)对2004年14号台风RANANIM("云娜")在登陆前近海加强及登陆初期的过程进行了54 h模拟,并加入人造台风优化初始场。结果表明:MM5能比较好地模拟出台风近海及登陆初期的移动路径及台风中心气压的变化。利用数值模拟结果,讨论了RANANIM(2004)台风在近海加强过程中的环流、动力和热力结构特征。发现在台风RANANIM近海加强的过程中对应有高空200 hPa净辐散场的存在,台风中心气压随净辐散值的增大而降低,反之亦然。净辐散值的减小对台风中心气压的快速升高有着预示的作用;垂直环流在强度和空间分布上发生了明显的变化。台风加强后,台风中心上方出现了明显的补偿性下沉气流;对流层低层存在明显的冷暖空气堆积,且当冷暖空气强度相当时有利于台风的增强;台风中心上方的正涡度柱逐渐发展为东西不对称分布,垂直方向上伸展高度保持不变或升高,而且在量值上也要更大。 相似文献
15.
The sensitivity of tropical cyclone (TC) intensification to the ambient rotation effect under vertical shear is investigated. The results show that the vortices develop more rapidly with intermediate planetary vorticity, which suggests an optimal latitude for the TC development in the presence of vertical shear. This is different from the previous studies in which no mean flow is considered. It is found that the ambient rotation has two main effects. On the one hand, the boundary layer imbalance is largely controlled by the Coriolis parameter. For TCs at lower latitudes, due to the weaker inertial instability, the boundary inflow is promptly established, which results in a stronger moisture convergence and thus greater diabatic heating in the inner core region. On the other hand, the Coriolis parameter modulates the vertical realignment of the vortex with a higher Coriolis parameter, favoring a quicker vertical realignment and thus a greater potential for TC development. The combination of these two effects results in an optimal latitude for TC intensification in the presence of a vertical shear investigated. 相似文献
16.
主要回顾热带气旋(TC)强度与结构变化的研究发展近况。以往热带气旋的理论研究认为在给定的大气和海洋热状况下，存在着一个TC所能达到的最大可能强度(MPI)。但实际上，海洋生成的热带气旋达到的最大强度普遍要比由MPI理论计算得到最大强度要低。近几年的研究表明，存在着内部和外部的不利因子通过对TC结构的改变来阻碍其加强，从而限制TC的强度。以往认为在诸多因子中，垂直风切变产生的内核区非对称结构与眼墙区下方海水上涌造成的海面冷却是制约TC达到MPI的主要因子。最新的研究进一步指出，产生TC非对称性的中尺度过程对其强度与结构的变化至关重要。中尺度过程包含有对流耦合的涡旋Rossby波、内外圈螺旋雨带、嵌于TC环流内的中尺度涡旋。外部的环境气流也是通过这些眼墙的中尺度过程影响到TC的强度与结构变化。 相似文献
17.
Shaoying LI Jun PENG Weimin ZHANG Jianping WU Qiang YAO Xiangrong YANG Tengling LUO 《大气科学进展》2023,40(3):464-482
The accurate forecasting of tropical cyclones(TCs) is a challenging task. The purpose of this study was to investigate the effects of a dry-mass conserving(DMC) hydrostatic global spectral dynamical core on TC simulation. Experiments were conducted with DMC and total(moist) mass conserving(TMC) dynamical cores. The TC forecast performance was first evaluated considering 20 TCs in the West Pacific region observed during the 2020 typhoon season. The impacts of the DMC dynamical core on forecasts o... 相似文献
18.
A western North Pacific tropical cyclone (TC) intensity prediction scheme (WIPS) is developed based
on TC samples from 1996 to 2002 using the stepwise regression technique, with the western North Pacific
divided into three sub-regions: the region near the coast of East China (ECR), the South China Sea region
(SCR), and the far oceanic region (FOR). Only the TCs with maximum sustained surface wind speed greater
than 17.2 m s-1 are used in the scheme. Potential predictors include the climatology and persistence factors,
synoptic environmental conditions, potential intensity of a TC and proximity of a TC to land. Variances
explained by the selected predictors suggest that the potential intensity of a TC and the proximity of a TC
to land are significant in almost all the forecast equations. Other important predictors include vertical wind
shear in ECR, 500-hPa geopotential height anomaly at the TC center, zonal component of TC translation
speed in SCR, intensity change of TC 12 or 24 h prior to initial time, and the longitude of TC center in
FOR.
Independent tests are carried out for TCs in 4 yr (2004-2007), with mean absolute errors of the maximum
surface wind being 3.0, 5.0, 6.5, 7.3, 7.6, and 7.9 m s-1 for 12- to 72-h predictions at 12-h intervals,
respectively. Positive skills are obtained at all leading time levels as compared to the climatology and
persistence prediction scheme, and the large skill scores (near or over 20%) after 36 h imply that WIPS
performs especially better at longer leading times. Furthermore, it is found that the amendment in TC
track prediction and real-time model analysis can significantly improve the performance of WIPS in the
SCR and ECR. Future improvements will focus on applying the scheme for weakening TCs and those near
the coastal regions. 相似文献
19.
利用数值模拟结果,该研究探讨了超级台风‘玛莉亚’的对流爆发(CBs)特征及与快速加强(RI)的关系。发现,(1)切变相对象限的内核CBs表现为由顺切变到逆切变的气旋式旋转,这有利于台风快速加强;(2)CBs的突然增长为即将到来的RI提供了预示性特征信号,同时,台风玛莉亚的RI过程引发剧烈的深对流;(3)自对流层底向上的对流增长角度分析,发现对流爆发与边界层高对流有效位能,次级环流的向上深层发展,增强的动量通量辐合等有关。 相似文献
20.
In this study,the effect of vertical wind shear(VWS)on the intensification of tropical cyclone(TC)is investigated via the numerical simulations.Results indicate that weak shear tends to facilitate the development of TC while strong shear appears to inhibit the intensification of TC.As the VWS is imposed on the TC,the vortex of the cyclone tends to tilt vertically and significantly in the upper troposphere.Consequently,the upward motion is considerably enhanced in the downshear side of the storm center and correspondingly,the low-to mid-level potential temperature decreases under the effect of adiabatic cooling,which leads to the increase of the low-to mid-level static instability and relative humidity and then facilitates the burst of convection.In the case of weak shear,the vertical tilting of the vortex is weak and the increase of ascent,static instability and relative humidity occur in the area close to the TC center.Therefore,active convection happens in the TC center region and facilitates the enhancement of vorticity in the inner core region and then the intensification of TC.In contrast,due to strong VWS,the increase of the ascent,static instability and relative humidity induced by the vertical tilting mainly appear in the outer region of TC in the case with stronger shear,and the convection in the inner-core area of TC is rather weak and convective activity mainly happens in the outer-region of the TC.Therefore,the development of a warm core is inhibited and then the intensification of TC is delayed.Different from previous numerical results obtained by imposing VWS suddenly to a strong TC,the simulation performed in this work shows that,even when the VWS is as strong as 12 m s-1,the tropical storm can still experience rapid intensification and finally develop into a strong tropical cyclone after a relatively long period of adjustment.It is found that the convection plays an important role in the adjusting period.On one hand,the convection leads to the horizontal convergence of the low-level vorticity flux and therefore leads to the enhancement of the low-level vorticity in the inner-core area of the cyclone.On the other hand,the active ascent accompanying the convection tends to transport the low-level vorticity to the middle levels.The enhanced vorticity in the lower to middle troposphere strengths the interaction between the low-and mid-level cyclonical circulation and the upper-level circulation deviated from the storm center under the effect of VWS.As a result,the vertical tilting of the vortex is considerably decreased,and then the cyclone starts to develop rapidly. 相似文献