Impacts of Madden–Julian oscillation on tropical cyclone activity over the South China Sea: Observations versus HiRAM simulations

This study investigates the impacts of Madden–Julian Oscillation (MJO) on tropical cyclone (TC) activity over the western North Pacific (WNP), with a focus on the South China Sea (SCS), based on results from observations and high-resolution atmospheric model (HiRAM) simulations. Observational analyses show that MJO imposes marked impacts on TC genesis over the SCS, with more (less) TC formations during the enhanced (suppressed) convection phases of MJO. Moreover, MJO also plays an important role in controlling the tracks of both westward-moving and eastward-moving TCs over the SCS. Results from HiRAM simulations indicate that, while the atmospheric model generates an MJO of a faster propagation, the general features of TC activity (including genesis and track) changes over the SCS associated with MJO variability have been properly reproduced by HiRAM.