摘要
在一个4种尺度(副热带高压、台风、β中尺度涡群和γ中涡尺度)共存的系统中,用正压原始方程模式数值地研究台风自组织及其强度变化问题。结果指出:(1)由于多尺度的相互作用,在初始台风衰减的过程中,在该台风的西南方经自组织形成了一个新的台风,其尺度、强度与初始台风相同。在初始台风衰减消失后,新的台风维持一定的强度继续向偏西北方向移动。(2)初始γ中涡的个数和位置对自组织起来的台风的强度有显著影响。其影响机制是非线性相互作用的结果在不同尺度层次的传递。γ中尺度层次或γ中—β中层次的相互作用直接影响到β中层次涡作用的结果,或者使双β中涡合并,或者使双β中涡分离。β中涡层次的相互作用直接影响到台风层次———新台风自组织的过程。这种影响最后反映到自组织起来的台风的强度和路径变化的宏观行为。
The progress concerning the physical mechanism responsible for changes of TC intensity has been made in some researches in terms of ideal models, which shows that meso-vortices located initially near the radius of maximum velocity of a TC may, in the way of the inward propagation of vorticity, form a new concentration of vorticity in the inner area leading TC increasing. The researches of this kind generally do not take the environmental flows into consideration and can be attributed to the category of systems of double scale with TC and meso-vortices. The systems in study are extended to ones with four-scale coexistence （ subtropical high, TC, meso-β and meso-γ vortices）. A shallow-water equation Model was integrated on a beta-plane centered at 20oN to study the typhoon self-organization and its intensity change in the systems. The results show （1） a new TC exhibits the southwest to the initial typhoon （TCA）, via self-organization, when TC A travels to the northwest and tends to gradually weaken, after TC A extinguished, the new TC maintains its intensity corresponding to one that TC A had initially, and continues to move to the northwest, and （2） the total number and positions of the initial meso-γ vortices can influence the intensity of the self-organized TC obviously, and the possible mechanism is as follows： the different interaction between meso-γ and meso-β vortices may result in the various consequences of the interaction of two meso-β vortices, merging together or departing away, and the interaction of meso-β vortices can bring the change of intensity and track of self-organized TC.
出处
《气象学报》
CAS
CSCD
北大核心
2005年第5期672-682,共11页
Acta Meteorologica Sinica
基金
国家自然科学基金项目(40333028)
关键词
台风
多尺度系统
自组织
强度变化问题
动力学
A multi-scale coexisting system, Typhoon, Self-organization, Intensity change.
