Halt of ocean wave growth under tropical cyclone extremes

Tropical cyclone (TC) intensity is represented by the maximum wind speed and central pressure. Ocean surface wave heights can also represent TC intensity because they are primarily determined by wind speeds. However, whether waves can continue to grow under extreme wind conditions during TCs remains unclear. The maximum wave forcing under the most severe TCs needs to be assessed for coastal disaster mitigation. Under extreme conditions, understanding of physical processes such as air–sea momentum flux and wave development or dissipation remains highly insufficient, and the actual spatial distribution of wind speed is also uncertain due to the lack of direct observations. Here, we utilise a drifting ocean wave buoy network, expanding spatial coverage in the open ocean, to identify wave growth under extreme TCs. Long-distance propagated swell waves can convey wave information directly from TC extreme wind regions where no direct wave observation exist. Comparison of swell energies between observations and numerical simulations indicates a halt in wave growth with increasing TC intensity. This finding is important for the design of coastal and ocean structures and can advance understanding of air–sea interactions under extreme wind conditions, which are among the main factors influencing TC intensity.