Kinetic energy spectrum of Typhoon 1713 Hato based on multi-scale numerical simulation

In this study, the TRAMS model is used to simulate the three-phase changes of water vapour, cloud water and rain introduced by Typhoon No. 13 Hato in 2017. The Fourier decomposition is used to analyze the multi-scale kinetic energy characteristics. It is found that the slope of the kinetic energy spectra of the asymmetric vortex and rainband scales are close to -3 in the inner core of the typhoon and the spiral rainband region. The slopes of the kinetic energy spectra of the convective systems in the middle and small scales show a complex variation of -5/3→-3→-5/3 except of the 5 km height. The kinetic energy transmission in the upper troposphere maintains the -3 characteristic in the inner core and the rainband region, and the overall slope in the periphery is close to -5/3. The strength of the energy transfer decreases with the increase of the distance of the typhoon center. It is found that the transformation of the kinetic energy of the asymmetric vortex to the rainband system is mainly concentrated in the middle and upper layers, and the transformation efficiency is low. The study shows that the water-phase change affects the energy transfer process inside the typhoon. The outer region is more consistent with inertial turbulence, while the inner core shows strong rotational flow characteristics.