查询词典 wind shear

Results show that during the snowstorm disaster, under the large scale background with "trough in south and ridge in north", strong cold air caused by prevailing northerly wind in northern Asia wedged into low level atmosphere over Southeast China and formed a "clod cushion". At the same time, warm-wet air was also transported to Southeast China by southerly wind. The vertical shear of winds from cold to warm airflows produced strong upward motion and then, the warm-wet air over the cold air wedge was driven to rise. Finally, the structure of "warm cover" and "cold cushion", as well as corresponding vertical circulation over the converging frontal zone came into being.

研究结果表明，灾害发生期间，中国北方中低层大气盛行偏北气流，使较强的偏北冷空气"楔入"中国东南部低层大气，构成低层"冷垫"，同时偏南暖湿气流源源不断地将大量水汽输送到中国东南部，冷暖气流交汇及其垂直切变导致强烈的上升运动，构成了"冷垫"上空的"暖盖"及"南槽北脊"反位相环流汇合锋区的垂直环流结构。

The approximate structure of nonlinear action of climatic atmosphere and ocean is: the nonlinear action decreases usually with increasing latitude, which is related to the role of the Coriolis force in fluid motion; the nonlinear action changes with the anomalous cyclonic or anticyclonic circulation shear, for instance, when the strength of anomalous eastward zonal circulation is comparable to that of anomalous meridional circulation, the nonlinear action is the strongest; wind stress plus gradient forces enhance the nonlinear action, etc..

气候海洋与大气非线性作用的大致结构是：通常与科里奥利力对流体运动的规范作用有关，非线性作用随纬度增加而减弱。距平流场的切变结构及其沿经向与纬向上强度的比较直接改变气候大气和海洋的非线性作用(比如，向东的距平环流强度与经向环流强度相当时，非线性作用最强)，较强的外部驱动使非线性作用加大等等。

The shear stress and tensile stress were increased obviously in the place of 388mm to centre of gyration of wind rotor comparing with other section where the phenomenon of stress concentration had for 1.5MW blade model.

在风速为14.6m/s时，1.5MW叶片模型风力机风轮转速达到400 rpm，但风轮风能利用系数为0.062，表明兆瓦级叶片模型与100W风力发电机不匹配。

The transverse wave disturbance along tangential base flow of circular vortex is discussed By using numerical method we study this instability of baroclinic flow which is mesoscale inertia wave instability on the cylindrical coordinate The influence of stratification stability N 2 , Coriolis parameter f 0 , the vertical shear of tangential wind z of the ambinent atmosphere and the latent heat on the growth rate of instability is studied From the above analysis and calculation, we can learn that there are Eady mode and mesoscale mode of transverse wave instability in circular vortex as well Furthermore we also learn that distribution character of mesoscale mode disturbance field of transverse wave instability, anomalistic "cats eye" structure of lower level and the character of the slowly spreading disturbance converges at low level and the quickly spreading disturbance converges at high level

作者中文名：李红金；陆汉城；宋晓亮；李鲲摘要：讨论涡旋大气中，存在沿切向基流传播的横波型扰动，并采用数值方法讨论了柱坐标系下圆形涡旋系统斜压气流中这类扰动的不稳定，这是一类中尺度的重力惯性波的不稳定。研究了涡旋环境大气的层结稳定度参数N2、切向风垂直切变Vz、凝结潜热、涡旋特性及科里奥利参数f0对不稳定增长率的影响。圆形涡旋中同样存在横波不稳定的Eady模态和中尺度模态，得到了中尺度模态的扰动场分布特征：流场的不规则"猫眼"结构及慢速传播的扰动均集中在低层，而快速传播的扰动均集中在高层的扰动特征。

Therefore, the moist potential vorticity analysis associated with the mesoscale convective system was researched in the paper, so as to reveal the moist potential characteristics of mesoscale convective system in typhoon circulation. The results showed that, during the generation stage, convective instability characterized by MPV1 was a favorable condition for forming MCS, while the vorticity which was caused by the slantwise isentropic surface and the vertical shear of the horizontal wind characterized by MPV2 was an inspiring mechanism. The specific process was that, the atmosphere exhibited the feature of strong convective instability at the low level of convection areas and the southeast areas, which included plenty of erratic energy. The slantwise ascended the stream transfer the erratic energy to northwest, where the stratification stability was small. As decreased, the cyclonic vorticity increased. On the other hand, the vorticity caused by the slantwise isentropic surface and the vertical shear of the horizontal wind inspired the release of convective instability and as a result that the MCS formed. During the development stage, the cyclonic vorticity increased quickly with the persistent decreasing of . Meanwhile, the inclination of isentropic linewas bigger than the absolute momentum line at middle level, which exhibited the feature of conditional symmetric instability , then the conditional symmetric instability was forced to release by the vorticity resulted from the slantwise isentropic surface and the vertical shear of horizontal wind, and the MCS developed.

结果表明，在对流形成阶段，MPV1即对流不稳定为MCS的形成提供背景不稳定条件，由MPV2即湿等熵面的倾斜和水平风的垂直切变而引起的涡旋发展作为强迫机制：MCS形成的区域及东南区域中低层是强对流不稳定层，蕴含丰富的不稳定能量，倾斜上升运动把对流不稳定区具有强不稳定能量的暖湿空气向西北中层的中性层结区输送，由于的减小，气旋性涡度增强，有利于形成对流，另一方面，由于湿等熵面倾斜和低空急流加强而引起的涡旋发展作为一种强迫机制激发对流不稳定能量得到释放，从而形成对流；在对流系统地发展阶段，由于低层的对流不稳定性进一步减弱，进一步减小，气旋性涡度进一步增强，有利于MCS的增强，中层等θe 线的倾斜度比绝对动量M 等值线的倾斜度大，对应有条件对称不稳定区域，满足条件对称不稳定条件，在湿等熵面倾斜和台风低空急流作用下引起的涡旋发展强迫对称不稳定能量释放，从而使得对流得以维持和加强。

The results show that the dynamic force and thermal conditions of forming the squall line were the convergence of cold air from Mongolia cold vortex and the warm-humid air current before west trough to form the convectional system at moderate 3 scale; the rapid development and southward shift of MβCSs was caused by a strong unstable stratification and the shear line of suitable vertical wind; a heavy hail occurred after a vertical liquid water content over 65 kg/m^2 was firstly measured by weather radar; a sharp reduction of VIL indicates that a disaster strong wind will occur at soon.

结果表明：蒙古冷涡旋转下甩冷空气与西风槽前的暖湿气流汇合，形成中p尺度的对流系统是飑线形成的前期动力和热力条件；强的不稳定层结和合适的垂直风切变导致了MβCSs的迅速发展和南压；在天气雷达首次观测到垂直液态水含量值超过65kg/平方公尺后2h内出现了大冰雹；垂直液态水含量的突然减小标志着灾害性大风的开始。

Divergence variation of snow storm indicated that the formation of negative divergent variation in lower-layer predicted the shear convergence and the snow storm generation. Nongeostrophic vorticity and divergence of wind advection contributed to the divergence variation largely.

暴雪切变线的散度变率诊断表明，低层散度负变率带及中心的生成和发展预示着未来时期内切变线辐合区的形成和发展及暴雪天气的发生，其中非地转涡度和风速平流的散度项对散度变率的贡献较大。

These appearances including V-style rabbet, advent of bounded weak echo region, stronger wind vertical shear and phenomenon of airflow convergence in radar precipitation echoes were all typical characteristics of strong convective weather echoes.

雷达回波上的"V"形槽口、有界弱回波的出现、较强的垂直风切变以及气流辐合现象，均为强对流天气回波的典型特征。

The membership card making process, you will power is converted to heat, wind, pressure, impact of shear stress, photosynthetic ability to coaction and then printing carrier use vector oilysludge isaelites, stress, stress, motivating various features of the supporting material such as molecular attraction to gravity comprehensive processing interface.

在会员卡制作后加工工序中，将电力转换成热力，风力，压力，冲击力，剪切力，光合化力等共同作用于印品载体，继而运用载体基材自有应力，机械设备各种功能应力，激发辅助材料分子引力等多重力综合于加工界面。

Evidence suggests that 1 under more stable stratification, the basic flow, if moving faster at low and high levels (particularly in the presence of jets there), allows a resulting meso-β unsteady wave to propagate eastward with respect to basic flow and even at greater velocity compared with it; 2 vertical windspeed shear of basic flow causes instabilities of the TWT perturbation; 3 considering the second derivative of basic-flow wind with respect to z (denoted by zz≠ 0 which is simply given as β* hereafter) the expression for the phase velocity of vortex Rossby wave is obtained, which is unidirectional in propagation with respect to basic flow; 4 VRoW has its physical origin from β*, i.e., from z-varying heterogeneities of y-direction averaged vorticity of the basic flow field; 5 VRoW phase velocity is associated with zonal wave number k, its energy is dispersive and the group velocity exists in the x direction; 6 when windspeed meets the condition of β*, TWT disturbance instability may be that of mixed VRoW and gravity wave; 7 if basic flow is subject to linear shear but does not meet the condition of β*, the TWT instability is that of inertia-gravity wave.

在大气层结比较稳定的情况下，如果基本气流在低层和高层较大(有可能存在低空急流和高空急流)，此时产生的β中尺度不稳定扰动相对于基流向东传播，甚至于快速向东传播。基本气流在垂直方向上的风速切变对于中尺度横波型的扰动起着不稳定的作用。如果考虑基流的二次切变，可以得到涡旋Rossby波的相速度表达式，涡旋Rossby波相对于基本气流是单向传播的。涡旋Rossby波产生的物理根源是基本流场的风速二次切变，亦即基本流场y方向的平均涡度在空间z方向上的不均匀所致。涡旋Rossby波的相速度与纬向波数也有关，它的能量是频散的，其在纬向x方向也存在群速度。在基本流场的风速存在二次切变时，横波型不稳定可能是混合的涡旋Rossby重力波的不稳定；而在基本流场的风速仅仅存在线性切变，不存在二次切变时，横波型扰动的不稳定则是重力惯性波的不稳定。

Neither the killing of Mr Zarqawi nor any breakthrough on the political front will stop the insurgency and the fratricidal murders in their tracks.

在对危险的南部地区访问时，他斥责什叶派民兵领导人对中央集权的挑衅行为。

In fact,I've got him on the satellite mobile right now.

实际上 我们已接通卫星可视电话了