The Dynamic Characteristics of Typhoon Vortex Spiral Waves and Its Transportation: Diagnostic Analyses

By adopting the moving‐coordinate on the typhoon center, the T BB time‐serial datasets of three target typhoons are analyzed through power‐spectrum analysis to investigate the wave train characteristics of typhoon spiral cloud bands. The results show that the T BB correlation coefficient field between the typhoon eye region and its surrounding areas has a remarkable spiral wave feature. The spiral waves in typhoon‐effected regions also show a conspicuous sub‐synoptic scale and meso‐scale characteristic, and their wave period and phase speed exhibit two peak values, one similar to internal gravity wave of over the 6h time scale and the other to the vortex Rossby wave of about 24h time scale. The high‐ and low‐level streams of typhoon spiral bands have close relation with its persistence and development. Besides, the T BB time departures show waves similar to the vortex Rossby wave train, and the wave path is similar to the Rossby wave transportation path too. Finally, a structure model of typhoon vortex spiral waves is put forward.