近三十多年来，由于观测，特别是卫星和下投式探空观测、数值模式和资料同化技术的改进以及对控制热带气旋（TC）移动物理过程理解的深入，TC移动路径预报的技巧得到了持续的改进，然而对TC强度预报的改进相对缓慢。其主要原因是控制TC强度变化的动力和物理过程比控制TC移动的动力和物理过程复杂得多，人们对其认识还不够深入，且缺少定量的理论估计。本项目将基于非定常卡诺热机的概念，通过引入TC热机的动力效率建立一个可用于定量估计TC强度变化的理论模型，其动力效率是TC内、外核惯性稳定性、非轴对称性结构、和环境风垂直切变等的函数，将通过观测资料分析和数值模拟定量地确定。由此建立的理论模型既能定性地解释影响TC强度变化的动力和热 力学机理，又能定量地估计不同动力和热力过程对TC强度变化的相对贡献及综合影响。基于这一理论模型，本项目拟发展一可用于实际TC强度预报的新的动力预报方案，为TC强度的业务预报服务。

Tropical cyclone (TC) track forecasts have improved steadily during the past three decades, due mainly to the availability of observations from satellites and airborne dropsondes, improvements in numerical weather prediction models, and advances in data assimilation techniques as well as improved understanding of the physical processes governing the motion of TCs. However, little improvement has occurred in predicting TC intensity. This is due partly to the fact that the dynamical and physical processes controlling TC intensity change are much more complicated than those governing TC motion, and partly to our lacked understanding and theoretical measure of those processes. Based on the concept of a nonsteady Carnot heat engine, this project attempts to develop a theoretical dynamical model system that can quantitatively estimate TC intensity change by introducing a dynamical-efficiency coefficient to the TC heat engine system. This coefficient is assumed to be a function of the TC inner- and outer-core inertial stability, the inner-core asymmetry, and environmental vertical wind shear (EVWS), and etc, and will be quantitatively determined by data analyses and ensemble numerical experiments. The theoretical model system so developed can help not only qualitatively understand the dynamical and physical processes controlling TC intensity change but also quantitatively estimate the relative and combined contributions of individual processes to TC intensity change. Based on the theoretical dynamical model system to be constructed, a new dynamical prediction scheme for real TC intensity will also be developed and tested, with an ultimate goal to provide an alternative operational TC intensity forecast guidance.