Numerical Study Of The Influence Of Initial Vortex Structure On The Intensification Of Tropical Cyclones

Although the vertical structure of tropical cyclone warm heart is closely related to the change of intensity, there is no direct observation of the three-dimensional warm-core structure of tropical cyclone. and how to construct the initial vortex in numerical prediction model is still a research topic. To explore the importance of vertical structure of warm core on the development of tropical cyclone, by using the mesoscale WRF model, three initial vortexes with same intensity but different height of warm centers are constructed, which are called the Low, Middle and High tests,respectively. The simulation result shows that the maximum wind speed radius in the Low and Mid tests begins to contract after 6h and the convection in the eye wall begin developing. And the intensity of the high warm core is stronger than that of the High test. The subsequent development speed in Low and Mid tests also faster than High test and reach the rapid intensification. The further diagnoses show that the initial CAPE value is higher and the low level vertical wind shear is stronger in Low test, which is favorable for convection development in the eye wall. The diabatic heating plays an important role in the formation of the warm core at high height, and the contraction rate of maximum wind speed radius is faster than the High test, and the intensity of the tropical cyclone increases rapidly. When three experiments'development are stable, the second intensity enhancement phenomenon is after 50h,resulting in this enhancement phenomenon is the main reason for the formation of high-level warm core. It is clear from this study that the warm center height of the initial vortex in the numerical prediction model has a significant effect on the development of simulated tropical cyclone intensity.