【摘要】 飓风是中 -α尺度系统 ,强风暴天气在飓风内分布不均匀 ,主要出现在眼墙区。眼墙区的气流结构及发生机理是飓风研究的重要问题。在张大林等用中尺度数值模式 (MM5 )对登陆美国的飓风 Andrew(1 992 )过程的精确数值模拟基础上 ,使用高分辨率模式输出资料进行了中尺度运动学分析 ,进而动力诊断了飓风眼区、眼墙及螺旋雨带区的梯度风不平衡 ,指出眼墙内深厚径向外流的发展是由深厚超梯度加速度造成 ,因此飓风的梯度风不平衡对飓风发展和维持起着重要作用。更多还原

【Abstract】 Hurricane is one kind of meso-α scale system. The severe weather distributes unevenly in it, mainly existing in eyewall. The flow structure and its formation mechanism are impartant subjects of hurricane research. This paper presents a mesoscale kinematic analysis of one hurricane case, which is based on the high resolution output of an explicit simulation of Hurricane Andrew landing on the USA in 1992 with the mesoscale regional numerical model MM5. The paper further documents the dynamical diagnosis of the gradient unbalance in the region of the eye, eyewall and the spiral rainbands of the hurricane. Based on the above analysis, the author points out that the development of the deep radial outflow is due to the deep supergradient layer in the eyewall, therefore, the gradient unbalance plays an important role in the evolution of the hurricane.更多还原