Net contributions of multiple oceanic warm and cold thermal events to tropical cyclone intensity revealed by idealized coupled simulations

The ocean serves as the energy source for tropical cyclones (TCs), and a TC typically encounters multiple oceanic warm and cold events during its lifecycle. While most existing studies emphasize individual thermal events, the net contribution of multiple warm and cold events to TC intensity remains unclear. We use a set of idealized coupled atmosphere–ocean simulations to examine how multiple ocean warm and cold thermal events affect TC intensity evolution throughout its lifecycle. Based on observational evidence, our experimental design includes one control experiment and 30 sensitivity experiments across three core scenarios (warm-anomaly dominated, cold-anomaly dominated, and warm-cold balanced anomalies). Relative to the control experiment, warm dominated experiments produce a stronger intensity evolution, cold dominated experiments produce a weaker decay, and the balanced experiments also lead to a slight increase. This response is fundamentally asymmetric, as the intensifying influence of warm events outweighs the weakening influence exerted by cold events with comparable magnitude. Moreover, this asymmetry increases with the magnitude of the oceanic thermal anomalies, and when the warm-anomaly amplitude is doubled, the simulated TC satisfies the rapid intensification criterion. These findings quantify the asymmetric forcing of ocean thermal structures on TCs, providing a crucial mechanistic basis for improving TC intensity forecasts. © The Author(s) 2026.