Evaluation of Tropical Cyclone Genesis Potential in the Alfred Wegener Institute Climate Model Version 3

This study evaluates the performance of the state-of-the-art Alfred Wegener Institute Climate Model version 3 (AWI-CM3) in reproducing tropical cyclone (TC) genesis potential, utilizing two distinct genesis potential indices (GPIs): the Emanuel–Nolan GPI (ENGPI) and Dynamic GPI (DGPI). By comparing historical simulations against observational and reanalysis data, we demonstrate that AWI-CM3 is a high-fidelity model capable of replicating the essential climatological annual mean, seasonal cycle, and El Niño–Southern Oscillation (ENSO)-modulated interannual features of TC genesis (TCG) potential. However, both indices exhibit specific limitations within the simulation. Specifically, the ENGPI in AWI-CM3 systematically overestimates the magnitude of tropical cyclone-favorable conditions, primarily due to biases in simulated sea surface conditions. Specifically, the model exhibits basin-dependent SST biases, with pronounced warm biases over the WNP, ENP, NIO, SIO, and SP, contrasting with a cold bias over the NA. In contrast, while the DGPI yields a more realistic magnitude, it displays a more complex spatial bias structure. Both indices in AWI-CM3 accurately capture the seasonal cycle of TCG potential across most basins, with the notable exception of the North Indian Ocean, which reflects both the model’s challenges in representing the seasonal retreat of regional monsoon circulations and certain inherent limitations of the GPIs themselves. Furthermore, AWI-CM3 faithfully captures the interannual modulation of TCG potential by ENSO, notwithstanding some regional discrepancies. Our evaluation provides critical insights into the necessity of a cautious application of GPIs in future climate projections using climate models.