Evaluation of Tropical Cyclone Characteristics in the SPEAR Large Ensemble Simulations

Abstract Tropical cyclone (TC) activity in the Seamless System for Prediction and EArth System Research (SPEAR) model large ensemble simulations is evaluated in this study. The climatological analysis indicates that though biases exist, the model overall captures the key TC characteristics, including track density, seasonality, landfall frequency, and precipitation. However, TC track density is overestimated over the Northwest Pacific (NWP) and underestimated over the Northeast Pacific. The model tends to underestimate TC landfall frequency across most continents. TC precipitation (TCP) bias varies regionally, and decomposition analysis reveals that it is primarily driven by biases in TC occurrence rather than by precipitation per TC, although the model tends to overestimate TCP in the inner‐core area of TCs. SPEAR reasonably simulates the observed temporal and spatial pattern of natural variability, including the El Niño‐Southern Oscillation (ENSO), the Pacific Decadal Oscillation (PDO) and the Atlantic Multidecadal Oscillation (AMO), and their TC modulations. Specifically, SPEAR simulates the increase in TC activity over the NWP and decrease over the North Atlantic (NA) during El Niño events and captures the increase in TC activity over the tropical Pacific Ocean during the PDO positive phase and the increase over NA during the AMO positive phase. TCP anomalies between different phases of the climate modes follow closely the TC track density anomalies, as they are mainly caused by TC occurrence differences. While SPEAR reproduces the TC landfall frequency anomalies associated with ENSO and AMO, it exhibits the opposite signal for PDO‐related anomalies compared to the observed signal.