Chinese Academy of Meteorological Sciences;
Beijing 100081;
Nanjing Institute of Meteorology;
Nanjing 210044nder two types of initial tropical cyclone structures that are characterized by high and low vorticity zones;
four sets of numerical experiments have been performed to investigate the interaction of a tropical cyclone with an adjacent mesoscale vortex (MSV) and its impact on the tropical cyclone intensity change;
using a quasi-geostrophic barotropic vorticity equation model with a horizontal resolution of 0.5 km. The results suggest that the interaction of a tropical cyclone characterized by a high vorticity zonal structure and an MSV would result in an intensification of the cyclone. Its central pressure decreases by more than 14 hPa. In the process of the interaction;
the west and middle segments of the high vorticity zone evolve into two peripheral spiral bands of the tropical cyclone;
and the merging of the east segment and the inward propagating MSV forms a new vorticity accumulation area;
wherein the maximum vorticity is remarkably greater than that in the center of the initial tropical cyclone circulation. It is this process of merging and strengthening that causes a greater pressure decrease in the center of the tropical cyclone. This process is also more complicated than those that have been studied in the past;
which indicated that only the inward transfer of vorticity of the MSV can result in the strengthening of the tropical cyclone.;
亮度变化; 热带飓风结构; 罗斯比波; 中尺度涡流; 自转正压;