共查询到18条相似文献，搜索用时 375 毫秒
1.
β涡旋的垂直结构及其对热带气旋移动的影响 总被引：3，自引：1，他引：3
应用准地转斜压模式数值模拟热带气旋的移动，分析大尺度β涡旋的水平和垂直结构及其对热带气旋移动的。研究结果表明，两β涡旋之间的准均匀流（通风气流）仍然与热带气旋的运动相关。 相似文献
2.
热带气旋强度影响其移动的物理机制 总被引：3，自引：2，他引：3
应用无基本气流的无辐射正压模式研究热带气旋强度影响其移动的物理机制，结果表明，（１）弱（强）热带气旋的大度尺β涡旋弱（强）通风气流速度小（大），因而其移速慢（快）（２）弱的与强的热带气旋的大尺度β涡旋的方位位相之差，通风气流方向之差都很小，因此其移向的差别也很小；（３）热带气旋移速振荡和移向摆动的周期与小尺度涡旋活动的周期相接近，在热带气旋内部区域；弱（强）热带气旋的切向风速小（大），小尺度涡旋活 相似文献
3.
热带气旋逆时针打转物理机制的研究 总被引：1，自引：2，他引：1
田永祥 《南京气象学院学报》1995,18(3):361-367
应用一个无基本气流的准地转斜压模式数值模拟热带气旋逆时针打转运动。分析结果表明：对称气流对非对称涡度的平流引起非对称流场中的小尺度涡旋和通风气流逆时针旋转；旋转的通风气流引导热带气旋作逆时针打转运动。 相似文献
4.
非对称环流的细致结构与台风路径的摆动 总被引：3，自引：1，他引：3
田永祥 《南京气象学院学报》1994,17(4):399-404
应用准地转三层斜压模式数值模拟热带气旋的移动，详细分析热带气旋非对称环流的三度空间结构及其与热带气旋移动的关系。结果表明：非线性涡度平流与线性β项相结合不但可以产生大尺度β涡旋对，而且还可产生小尺度涡旋对；这两种不同尺度的非对称涡旋不断相互作用，导致热带旋移速的振荡和移向的摆动。 相似文献
5.
双热带气旋相互作用的研究 总被引：7，自引：1，他引：6
采用无基本气流的无辐散正压模式模拟了双热带气旋的运动。应用非对称理论研究了双热带气旋的相互作用。双热带气旋中的每个热带气旋主要由通过其中心的非对称气流（即通风气流）作用而移动。这股非对称气流是由其自身的线性和非线性效应产生的非对称涡旋与其配对热带气旋形成的非对称涡旋相叠加而引起的。 相似文献
6.
热带气旋的水平尺度对其移动的影响 总被引：3，自引：0，他引：3
应用无基本气流的无辐无正压模式研究热带气旋的水平尺度对其移动的影响,水平尺度较小的（较大的）热带气旋向西北偏北（西北偏西）移动,水平尺度较小的（较大的）热带气旋使其大尺度β涡旋逆时针旋转一个较小的（较大的）角度αｉ。热带气旋的移向θｃ与角度αｉ有关,即θｃ≈３６０°－αｉ。因此,热带气旋的移向随其水平尺度的增大而逆时针向偏转。 相似文献
7.
相同强度双台风相互作用的物理机制 总被引：2，自引：1，他引：1
在无基本气流的假定下,应用无辐数正压模式研究双台风相互作用的物理机制。台风Ａ位于观风Ｂ以西,两台风相距６０ｋｍ,且具有相同的强度。在台风Ａ（台风Ｂ）的非对称流场中,由台风Ａ（台风Ｂ）的线性β效应产生的非对称涡旋的方位相位与由台风Ｂ（台风Ａ）形成的非对称涡旋方位相位相反（相同）。因此,台风Ａ（台风Ｂ）的大尺度非对称涡旋较弱（较强）。小尺度涡旋逆时针旋转导致台风Ａ逆时将打转。稳定的偏南非对称气流使台风 相似文献
8.
热带气旋运动的动力学研究进展 总被引：30，自引：7，他引：23
热带气旋运动是由各种形式的外部强迫、内部过程及其相互作用所决定的。特别是环境气流与气旋环流以及β效应之间的相互作用可以产生次级的非对称气流,使热带气旋偏离大尺度环境气流的引导。这种偏差,被称为广义的β漂移。本文讨论了控制β漂移的物理因子和物理过程,尤其是涡旋结构与环境气流切变对它的影响,以及β漂移在热带气旋路径预报上的应用。另外,还总结了双台风相互作用、热带气旋摆动和与下垫面强迫有关的物理过程的影响。 相似文献
9.
热带气旋周围的流场可以分解为对称涡旋、引导气流以及将这两个部分剔除后的非对称环流。在一个有静止环流背景的正压模式中，非对称环流是与定义为风暴运动矢量和引导气流之差的传播矢量相联系。Ｃａｒｒ导出的关于非地称环流及相应的传播矢量的解析设定可用于路径动力预后模式的初始条件中。 相似文献
10.
我们采用无辐散正压数值模式,在无基本气流的条件下研究了热带气旋结构对其运动的一些作用。正如 DeMaria 先前所指出的,初始最大风速对涡旋轨迹影响甚微。与β效应相联系的涡旋移动十分敏感地依赖于离中心300至1000km 范围内的气流强度。如果此圆环内的气流气旋性加强,则涡旋轨迹也会气旋性地转向,在北半球其移动更偏向于西。通过分解出对称和不对称环流,我们讨论了β漂移的动力学。对称气流经历了最大风速稍微减弱和在600km 以外激发出一反气旋环流的过程。不对称环流由方位1波环流所支配,中心东侧有一反气旋环流圈,西侧有一气旋性环流圈,两环流圈之间有一近于均匀的,尺度较宽的通风气流。涡旋移动的速度和方向几乎等同于该通风气流在涡旋内有显著气旋性环流区域上的平均值。模式流函数趋势方程的分析证实,线性β项导致初始不对称环流圈的形成。对称涡旋气流平流不对称环流,这一非线性项使两环流圈之间的内部区域发生扭曲,并使通风气流的方向由向北演变成向西北。由于该项几乎与线性β强迫相平衡,所以流函数时间趋势(及涡旋移动)主要由通风气流平流对称涡旋这一项决定。 相似文献
11.
Tian Yongxiang 《Acta Meteorologica Sinica》1995,9(3):338-348
The tropical cyclone motion is numerically simulated with a quasi-geostrophic baroclinic model.The flow field of a tropical cyclone is decomposed into its axisymmetric and asymmetric components.The relation between the ventilation flow vector and the motion vector of the tropical cyclone is investigated.The results of numerical experiments indicate:(1) There are both large-scale beta gyres and small-scale gyres in the asyrnmetric flow field.(2) The interaction between small-scale gyres and large-scale beta gyres leads to the oscillation of translation speed and translation direction for the tropical cyclone.(3) There are the large deviations between the ventilation flow vector calculated by means of Fiorino and Elsberry's method and the motion vector of tropical cyclone.(4) The ventilation flow vector computed using the improved method closely correlates with the motion vector of the tropical cyclone. 相似文献
12.
VENTILATION FLOW IN A BAROCLINIC VORTEX RELATED TO TROPICAL CYCLONE MOTION 总被引：1，自引：0，他引：1 
下载免费PDF全文
下载免费PDF全文 田永祥 《Acta Meteorologica Sinica》1995,(3)
The tropical cyclone motion is numerically simulated with a quasi-geostrophic baroclinic model.The flow field of a tropical cyclone is decomposed into its axisymmetric and asymmetric components.The relation between the ventilation flow vector and the motion vector of the tropical cyclone is inves-tigated.The results of numerical experiments indicate:(1) There are both large-scale beta gyres andsmall-scale gyres in the asyrnmetric flow field.(2) The interaction between small-scale gyres andlarge-scale beta gyres leads to the oscillation of translation speed and translation direction for the tropi-cal cyclone.(3) There are the large deviations between the ventilation flow vector calculated bymeans of Fiorino and Elsberry's method and the motion vector of tropical cyclone.(4) The ventila-tion flow vector computed using the improved method closely correlates with the motion vector of thetropical cyclone. 相似文献
13.
The dynamics of tropical cyclone is investigated in a nondivergent barotropic model with no basic flow. The effect of nonlinear term on the movement and development of tropical cyclone is emphatically demonstrated. The advection of asymmetric vorticity by the symmetric flow(AAVS) produces the small-scale gyres(SSGs). The SSGs counterclockwise rotate around the tropical cyclone center. The interaction of SSGs with the large-scale beta gyres(LSBGs) leads to the oscillation in translation speed and vacillation in translation direction for tropical cyclone. The advection of symmetric vorticity by the asymmetric flow(ASVA) steers the symmetric circulation of tropical cyclone. The ventilation flow vector determined by the asymmetric flow is close correlated with the motion vector of tropical cyclone. The nonlinear advection of relative vorticity is an order of magnitude greater than the linear advection of planetary vorticity, However, the asymmetric circulation created by the planetary vorticity advection provides a background condition for anomalous motions of the tropical cyclone. The combination of the linear and nonlinear effects results in accelerated, decelerated, changing direction and/or counterclockwise looping motions of the tropical cyclone. 相似文献
14.
The dynamics of tropical cyclone is investigated in a nondivergent barotropic model with nobasic flow. The effect of nonlinear term on the movement and development of tropical cyclone isemphatically demonstrated. The advection of asymmetric vorticity by the symmetric flow (AAVS)produces the small-scale gyres (SSGs). The SSGs counterclockwise rotate around the tropicalcyclone center. The interaction of SSGs with the large-scale beta gyres (LSBGs) leads to theoscillation in translation speed and vacillation in translation direction for tropical cyclone. Theadvection of symmetric vorticity by the asymmetric flow (ASVA) steers the symmetric circulationof tropical cyclone. The ventilation flow vector determined by the asymmetric flow is closecorrelated with the motion vector of tropical cyclone. The nonlinear advection of relative vorticityis an order of magnitude greater than the linear advection of planetary vorticity, However, theasymmetric circulation created by the planetary vorticity advection provides a background conditionfor anomalous motions of the tropical cyclone. The combination of the linear and nonlinear effectsresults in accelerated, decelerated, changing direction and/or counterclockwise looping motions ofthe tropical cyclone. 相似文献
15.
EFFECT OF THE LINEAR BETA TERM ON MOVEMENT AND DEVELOPMENT OF TROPICAL CYCLONE 总被引：2，自引：0，他引：2 下载免费PDF全文
下载免费PDF全文 The dynamics of tropical cyclone is investigated in a nondivergent,barotropic model with nobasic flow.The effect of linear beta term on the movement and development of tropical cyclone isemphatically demonstrated.The streamfunction tendency due to the symmetric component of linearbeta term appears in a dipole-like pattern with an east-west symmetry,which maintains andintensifies the large-scale beta gyres and causes the tropical cyclone to have a westerly movingcomponent.The streamfunction tendency due to the asymmetric component of linear beta termarises in an ellipse pattern with a north-south major axis,which weakens the tropical cyclone.Thestreamfunction tendency due to the asymmetric component of linear beta term and the intensity oflarge-scale cyclonic beta gyre synchronously vary in a fluctuating manner with time. 相似文献
16.
The dynamics of tropical cyclone is investigated in a nondivergent,barotropic model with no basic flow.The effect of linear beta term on the movement and development of tropical cyclone is emphatically demonstrated.The streamfunction tendency due to the symmetric component of linear beta term appears in a dipole-like pattern with an east-west symmetry,which maintains and intensifies the large-scale beta gyres and causes the tropical cyclone to have a westerly moving component.The streamfunction tendency due to the asymmetric component of linear beta term arises in an ellipse pattern with a north-south major axis,which weakens the tropical cyclone.The streamfunction tendency due to the asymmetric component of linear beta term and the intensity of large-scale cyclonic beta gyre synchronously vary in a fluctuating manner with time. 相似文献
17.
ＶｅｒｔｉｃａｌＳｔｒｕｃｔｕｒｅｏｆＢｅｔａＧｙｒｅｓａｎｄＩｔｓＥｆｆｅｃｔｏｎＴｒｏｐｉｃａｌＣｙｃｌｏｎｅＭｏｔｉｏｎＴｉａｎＹｏｎｇｘｉａｎｇ（田永祥）ａｎｄＬｕｏＺｈｅｘｉａｎ（罗哲贤）（ＮａｍｉｎｇＩｎｓｔｉｔｕｔｅｏｆＭｅｔｅｏｒｏｌ... 相似文献
18.
自20世纪90年代后期以来,热带气旋强度变化研究越来越受到人们的重视,随着研究的不断深入,热带气旋强度变化研究取得了可喜的进展,文中总结近年来热带气旋强度变化的主要研究成果,主要包括(1)热带气旋的发生、发展和最大可能强度的研究;(2)行星涡度梯度、环境均匀流、环境流场垂直切变以及热带气旋外流与环境流的相互作用对热带气旋强度的影响及物理机制;(3)热带气旋结构与强度的变化关系,着重总结环境流场导致的非对称结构变化而引起的热带气旋强度变化以及对涡旋倾斜发展理论验证,分析了涡旋Rossby波的最新研究;(4)海洋热状况变化以及海洋飞沫对热带气旋强度的影响研究成果。分析指出,今后进一步开展用现代化卫星探测资料研究热带气旋强度变化外,还应加强热带气旋外流与环境流场的相互作用,海-气交界面的参数化问题,热带气旋结构变化与TC强度变化关系以及这种关系的物理本质的研究,通过深入研究,认识热带气旋强度变化的物理机制,提高热带气旋强度变化的预报能力。 相似文献