Evaluation of a time-dependent model for the intensification of tropical cyclones

However, the intensification rate varies in proportion to the surface exchange coefficient for momentum C-d, while the Emanuel model growth rate is insensitive to C-d. Furthermore, although the tendency diagnosed by Emanuel is qualitatively similar to the numerical model result during phase II, it is not quantitatively similar. The present analysis finds the inclusion of non-gradient wind effects in the theoretical framework of Emanuel's study produces an intensification rate that is quantitatively similar to the numerical model results.

The neglect of non-gradient wind effects in Emanuel's study may be the reason for the different dependence of its intensification rate on C-d compared to that of the numerical model. Other aspects of Emanuel's study in the context of recent research on TC intensification are discussed.