Extreme Atlantic hurricane seasons made more likely by ocean warming

Abstract. Tropical cyclones are among the most damaging and fatal extreme weather events. An increase in Atlantic tropical cyclone activity has been observed, but attribution to global warming remains challenging due to large inter-annual variability and modelling challenges. Here we show that the increase in Atlantic tropical cyclone activity since the 1980s can be robustly ascribed to changes in atmospheric circulation as well as sea surface temperature (SST) increase. Using a novel weather pattern based statistical model, we find that the forced warming trend in Atlantic SSTs over the 1982–2018 period increased the probability of extremely active tropical cyclone seasons by 14 %. Seasonal atmospheric circulation remains the dominant factor explaining both inter-annual variability and the observed increase. Our weather pattern-based statistical decomposition helps to understand the role of atmospheric variability for the Atlantic tropical cyclone activity and provides a new perspective on the role of ocean warming.