On Maximum Potential Intensification Rate (MPIR) of a Tropical Cyclone: An Observational Perspective

In this study, a concept of maximum potential intensification rate (MPIR) of a tropical cyclone is introduced and demonstrated based on the best track tropical cyclone data from all ocean basins. By definition, the MPIR is the upper bound of the intensification rate that a TC can reach given favorable atmospheric and oceanic thermodynamic conditions. Similar to the empirically fitted functional relationship between the maximum potential intensity (MPI) and sea surface temperature (SST) documented in previous studies, here we report an empirically fitted functional relationship between MPIR and SST. Further analysis shows that the MPIR is a strong function of the MPI, indicating that the MPIR may be largely determined by the MPI. It is shown that the observed features can be understood based on a simplified dynamical system relevant to tropical cyclone intensification.