8014号热带气旋发生发展过程的能量学诊断研究

TROPICAL CYCLONE IN SOUTH CHINA SEA IN ENERGETICS STUDY

关键词:  南海  热带气旋  动能和总位能收支

Key words:  South China sea  Tropical cyclone  Budget of kinetic energy and total potential energy

摘要:

利用动能和总位能收支方程,对8014号强热带风暴过程进行了能量学诊断研究。结果表明,地转作用是该热带气旋中辐散风动能向旋转风动能转换的主要物理机制;非绝热加热是热带气旋发展的主要能源,其对总位能的制造大部分用于次网格耗散和侧边界输出,只有一小部分被转化为辐散风动能;两个转换函数C(P,K_x)和C(K_x,K_ψ)在时空分布上具有很好的一致性;该热带气旋与周围环境场有明显的能量交换,在高层有总位能和旋转风动能输出,在低层有辐散风动能输入;在总动能收支中,辐散风作功是主要的功能产生项,旋转风作功主要是消耗动能。

Abstract:

A diagnostic study is presented with respect to budget equations of rotational and divergent components of kinetic energy as well as total potential energy in an open system for a case of strong tropical storm 8014 (Ruth) which occurred and developed in the South China sea. It is shown that for the tropical cyclone of interest, geostrophic effect is the main physical mechanism of conversion from divergent to rotational kinetic energy; diabatic heating supplies most of its energy for development and a large part of the total potential energy produced by it is consumed in subgrid dissipation and lateral boundary outward flux, leaving the remainder to be converted to kinetic energy of the divergent component; two of the functions of conversion [C(P,K_x] and C(K_x,K_ψ) are in good agreement in the distribution of space and time; there is significant exchange of energy between the storm and environment, displayed by the output of total potential energy and rotational kinetic energy at the upper level against the input of divergent kinetic energy at the lower level; the work done by the divergent component acts as major generator of kinetic energy and that by the rotational component as the consumer, in the total budget of energy.