The interaction between a tropical cyclone (TC) and the underlying ocean is investigated using an atmosphere–ocean coupled model. The atmospheric model is developed from the Pennsylvania State University (Penn State)–National Center for Atmospheric Research (NCAR) mesoscale model version 4 MM4 and the ocean model consists of a mixed layer and an inactive stagnant layer beneath. Coupling between the atmosphere and the ocean models is achieved through wind stress and surface heat and moisture fluxes that depend on the sea surface temperature (SST). In the absence of a background flow, the atmospheric component consists of only a predefined vortex with an initial central pressure and the radius of the 15 m s−1 wind. The basic control experiments demonstrate that the coupled model can simulate the development of a TC and its interaction with the ocean. Changes in TC intensity are sensitive to those of SST and the response is almost instantaneous. An SST of ∼27°C is found to be the threshold for TC de... Abstract The interaction between a tropical cyclone (TC) and the underlying ocean is investigated using an atmosphere–ocean coupled model. The atmospheric model is developed from the Pennsylvania State University (Penn State)–National Center for Atmospheric Research (NCAR) mesoscale model version 4 MM4 and the ocean model consists of a mixed layer and an inactive stagnant layer beneath. Coupling between the atmosphere and the ocean models is achieved through wind stress and surface heat and moisture fluxes that depend on the sea surface temperature (SST). In the absence of a background flow, the atmospheric component consists of only a predefined vortex with an initial central pressure and the radius of the 15 m s−1 wind. The basic control experiments demonstrate that the coupled model can simulate the development of a TC and its interaction with the ocean. Changes in TC intensity are sensitive to those of SST and the response is almost instantaneous. An SST of ∼27°C is found to be the threshold for TC de...