小尺度系统对涡旋自组织的影响

Influences of a Small-Scale System on the Self-Organization of Vortices

摘要:

在涡旋自组织动力学的框架内,利用ƒ平面准地转正压模式讨论小尺度涡旋系统对两个中β尺度涡旋的自组织过程的影响。4组数值试验表明:小尺度涡旋的存在,可能会改变双涡相互作用的终态,使原本不合并的两个涡旋组织起来;双涡相互作用的终态对小尺度涡旋的初始位置敏感;存在"Z"型敏感区域,当小尺度涡旋出现在这一区域时,就有可能改变双涡相互作用的终态;小尺度涡旋对双涡相互作用产生影响需具备4个条件,即初始位于敏感区内,有足够的强度,距离适当且生存时间足够长。

Abstract:

In the framework of vortex self-organization dynamics,the influences of a small-scale system on the self-organization process of two meso-β vortices are investigated by utilizing an ƒ-plane 2D quasi-geostrophic barotropic vorticity equation model.Four groups of numerical experiments are performed,and the results show that: the small-scale system may change the two vortices interaction and trigger the merging process;the final state is sensitive to the initial location of the small-scale system;there is a "Z" shape sensitive region,when a small-scale vortex initially appears there,resulting in the fact that the interaction stage of the two vortexes is more likely to be changed;for altering the vortices interaction results,the small-scale system should satisfy the following three necessary conditions:an initial position in the "Z" shape sensitive region,proper distances to other two vortices,enough intensity and longer life cycle.