飓风中的涡旋罗斯贝波

文中从柱坐标系下的正压无辐散涡度方程出发,用WKBJ方法求解方程,发现在飓风中存在类似于行星罗斯贝波的涡旋罗斯贝波,这种波的形成主要是由于飓风中基态涡度垂直分量的径向梯度所决定。利用一次飓风过程的精确数值模拟所输出高分辨的资料,计算了飓风中径向涡度梯度的分布,指出这类波动主要存在于眼墙和眼心中。波动结构分析表明,波动能量具有径向频散,这有可能是飓风暖心结构的一种形成机制。最后用波射线法讨论了定常涡旋罗斯贝波的径向频散

VORTEX ROSSBY WAVES IN HURRICANE

Through solving the nondivergent inviscid linear vorticity equation in cylindrical coordination of barotropic atmosphere with WKBJ method, the authors point out that one kind of wave, named vortex Rossby wave, which is similar to planetary wave, exists in hurricane, its formation is due to the gradient of vertical vorticity component of basic state. According to the distribution of the radial gradient of vertical vorticity component of hurricane, which is calculated with high resolution output from one explicit numerical simulation of a hurricane case, this kind of wave mainly emerges in eye and eyewall. At the same time, the analysis of wave structure declares that there is radical dispersion of the disturbing energy, which may be one of the formation mechanisms for warm core in hurricane. Finally, the radial dispersion of stationary vortex Rossby wave is discussed with wave ray method.