Analysis of distribution and transformation characteristics of multi-scale energy of typhoon Higos in 2020

The No.7 typhoon Higos in 2020 caused strong wind and torrential rain in Guangdong Province. A detailed study of its multi-scale energy distribution and transformation characteristics will help us better understand and prevent similar typhoon disasters. In this paper, the WRF regional numerical model is used to simulate typhoon Higos. The simulation results were separated into large scale background field (> 2 000 km), meso-α scale (200~2 000 km) and meso-micro-β scale (< 200 km) by Barnes filtering method. The distribution of kinetic energy, effective potential energy and their changes are calculated for the three scale components. Here are the results. (1) During the active period of typhoon Higos, the large scale background field kinetic energy first increases and then keeps constant. Meso-α scale kinetic energy first increases and then decreases. The change of meso-micro-β scale kinetic energy is not obvious. The main source of kinetic energy is the conversion of effective potential energy and the work done by the pressure gradient force, and the main dissipation is horizontal transport and cross scale conversion. All three scales of kinetic energy are mainly distributed in the lower troposphere. (2) The effective potential energy of large scale background field repeats the process of first increasing and then decreasing twice. Meso-α and meso-micro-β scale effective energy first increases and then decreases. The main source of effective potential energy is diabatic heating, and the main dissipation is converting into kinetic energy, horizontal transport and cross scale conversion. All three scales of effective potential energy are mainly distributed in the upper troposphere. (3) The energy conversion areas of typhoon Higos are mainly the upper troposphere of the typhoon eye wall and the central dense overcast area within 200 km from the typhoon center, the upper troposphere around typhoon in 200-700 km from the typhoon center, and the lower troposphere within 400 km from the typhoon center.