资源环境科技发展态势分析平台

Azimuthally asymmetric perturbations are important to hurricanes because they can influence the track, structure, and intensity of a hurricane. In this work, we applied space-time spectral analysis on both dynamic and thermodynamic fields of these perturbations and found two distinct power peaks in most of the fields. We obtained the structure of each mode by first filtering the fields through a frequency-wavenumber spectral window selected for each mode and then regressing these fields on an index based on the filtered radar reflectivity. We found that the fast-propagating wave is dominated by perturbations near the eyewall, and its structure is similar to that of the unstable mixed vortex Rossby inertia gravity wave. The other peak corresponds to a slow-propagating wave that has comparable perturbations in and beyond the eyewall. The slow wave has a retrograde intrinsic propagating speed and has a vertical structure that resembles that of convectively coupled waves.