Revisiting the intraseasonal, interannual and interdecadal variability of tropical cyclones in the western North Pacific

This paper reviews the recent progress and research on the variability of tropical cyclones (TCs) at different time scales. Specific focus is placed on how different types of external forcings or climatic oscillations contribute to TC variability in the western North Pacific (WNP). At the intraseasonal scale, recent advances on the distinctive impacts of the Madden-Julian Oscillation (MJO), the Quasi-biweekly Oscillation, and the asymmetric MJO modulation under different El Nino-Southern Oscillation (ENSO) states, as well as the influences of the Pacific-Japan teleconnection, are highlighted. Interannually, recent progress on the influences of the ENSO cycle, different flavors of ENSO, and impacts of Indian Ocean warming is presented. In addition, the uncertainty concerning interdecadal TC variations is discussed, along with the recently proposed modulation mechanisms related to the zonal sea surface temperature gradient, the North Pacific Gyre Oscillation, and the Pacific Decadal Oscillation (PDO). It is hoped that this study can deepen our understanding and provide information that the scientific community can use to improve the seasonal forecasting of TCs in the WNP.