Chanchu台风(0601)精细结构中的熵流特征分析

在耗散结构理论的基础上，根据热力学第二定律推导出了熵平衡方程。利用高分辨率模式输出资料通过对比Chanchu台风(0601)螺旋雨带上游、中游和下游及眼壁附近不同区域对流单体和熵流分布情况，揭示出负熵流值与台风的强对流单体有密切联系。基于负熵流与台风精细结构的配置分析，研究中尺度范围内熵流随Chanchu台风发生、发展、消亡各阶段的演变特征。分析表明，对流单体在从雨带上游至下游的演变过程中，熵流分布特征也会发生相应的变化，强对流单体与负熵流大值区相对应；当对流单体减弱，负熵流也随之减弱；当单体最后合并并汇入眼墙时，负熵流彼此合并旋入眼墙，有助于眼墙中深厚对流的维持和发展；此外，负熵流对于Chanchu台风在各发展阶段的强度变化也有一定的指示意义，揭示了负熵流对大气系统的组织化作用。 

ENTROPY FLOW CHARACTERISTICS OF TYPHOON Chanchu's (0601) FINE STRUCTURE

Based on dissipation structure theory, an entropy balance equation is derived from the Gibbs relation, according to the second law of thermodynamics. The distribution of convective cells and entropy flow in the upstream, midstream and downstream of spiral rainband and eyewall are examined using a high-resolution simulation data of Typhoon Chanchu (2006). By comparing the distribution of entropy flow in different parts of spiral rainband and eyewall, we find that the distribution of negative entropy flow is in close contact with deep convective cells. The evolution characteristics of the entropy flow accompanying with the onset, development and extinction of the typhoon are also analyzed based on the configuration of negative entropy flow and fine structure of the typhoon. It is indicated that in the evolution of convective cells from upstream to downstream of the rainband, the distribution characteristics of entropy flow will change accordingly. Deep convective cells correspond with a large-value region of negative entropy flow. As convective cells weaken, the absolute value of negative entropy flow decreases. When the convective cells merge and flow into the eyewall, the negative entropy flows aggregate in the eyewall and the highest negative entropy comes into being, which contributes to the maintenance and development of deep convection in the eyewall. Furthermore, negative entropy flow may be a significant indicator for intensity variation of the typhoon, suggesting the systematization effect of negative entropy flow on atmospheric systems.