Tropopause temperature drives tropical cyclone simulation diversity
Tropopause temperature biases create major tropical cyclone differences in models; cooler air boosts storm potential intensity, raising global cyclone frequency and hurricanes in experiments.
Tropical cyclones are a key focus of climate research, but models often disagree on storm behavior even with identical sea surface temperature data. Mahoney et al. [2026] identify a major, overlooked factor: temperature biases at the tropopause. Cooler tropopause temperatures strengthen storms by cooling their upper-level outflow, boosting their potential intensity. In model experiments, this effect increased global cyclone frequency by 35% and North Atlantic hurricane frequency by 80%. The findings reveal that upper-atmosphere temperatures are as critical as ocean surface temperatures for accurate storm prediction, refining future climate projections, and risk preparation worldwide.