Abstract:Taking super typhoon Saomai (2006) which intensified and weakened rapidly over coastal waters as an example, based on the nonlinear dynamic system research methods, the energy development conditions of tropical cyclone (TC) are analyzed from a kinetic view by the use of NCEP/NCAR reanalysis data with horizontal resolution of 1°×1° and vertical resolution of 11 layers. Some physical parameters that can analyze and predict TC intensity, such as non-thermal wind vorticity, thermal wind bias and its vertical shear, are derived as operational forecast indicators. Results show that the existing of a negative non-thermal wind vorticity center near the TC center is favorable to its offshore rapid intensification. Non-thermal wind vorticity variations and the TC central pressure changes are in a better consistency. When the wave disturbance propagates upward, the thermal wind bias is positive/negative in the intensifying/weakening process. When the external wave disturbance spreads to the inner core, the thermal wind bias shear is negative/positive in the intensifying/weakening phase. And the features of thermal wind bias and its vertical shear are more obvious in the lower troposphere. When the wave disturbance propagates upward and from the external to inner core of TC, non-thermal wind vorticity is positive, thermal wind bias is negative and its vertical shear is negative in the intensifying process, and vice versa.