An approach for constructing the large-member ensemble using multiple parameterization schemes for typhoon research

This study presents high-resolution ensemble simulations for a tropical cyclone over the North Pacific Ocean and adjacent sea basins with a sizable number of members. The parameterized physical processes, precisely cloud microphysics, cumulus parameterization, turbulence processes, planetary boundary layer processes, radiation processes, and surface fluxes, are crucial for simulating typhoons’ emergence, intensification, propagation, and weakening in weather predictions. To consider the uncertainty in the parameterizations, we generated an ensemble forecasts with a valid combination of these parameterization schemes. This study uses the Scalable Computing for Advanced Library and Local Ensemble Transform Kalman Filter model (SCALE-LETKF). A set of initial conditions was generated by assimilating conventional observations. The case study involving Typhoon Dolphin (2020) demonstrates the approach's effectiveness in capturing the typhoon's behaviour and predicting its trajectory and intensity. The results could have implications for improving the accuracy of typhoon forecasts and potentially enhancing early warning systems for these natural disasters.