Tropical Cyclone Climatology in a Global-Warming Climate as Simulated in a 20 km-Mesh Global Atmospheric Model: Frequency and Wind Intensity Analyses

TLDR

The study investigates how tropical cyclone frequency and wind intensity may change in a future greenhouse‑warmed climate using a high‑resolution global atmospheric model. Two 10‑year experiments—present‑day and greenhouse‑warmed with higher sea‑surface temperatures and greenhouse‑gas concentrations—were run with a 20 km‑mesh MRI/JMA model. The warm‑climate run shows a ~30 % global reduction in cyclone frequency (except the North Atlantic) but a higher number of intense storms and greater peak wind speeds (7.3 m s⁻¹ NH, 3.3 m s⁻¹ SH), indicating increased risk of devastating cyclones worldwide.

Abstract

Possible changes in the tropical cyclones in a future, greenhouse-warmed climate are investigated using a 20 km-mesh, high-resolution, global atmospheric model of MRI/JMA, with the analyses focused on the evaluation of the frequency and wind intensity. Two types of 10-year climate experiments are conducted. One is a present-day climate experiment, and the other is a greenhouse-warmed climate experiment, with a forcing of higher sea surface temperature and increased greenhouse-gas concentration. A comparison of the experiments suggests that the tropical cyclone frequency in the warm-climate experiment is globally reduced by about 30% (but increased in the North Atlantic) compared to the present-day-climate experiment. Furthermore, the number of intense tropical cyclones increases. The maximum surface wind speed for the most intense tropical cyclone generally increases under the greenhouse-warmed condition (by 7.3 m s−1 in the Northern Hemisphere and by 3.3 m s−1 in the Southern Hemisphere). On average, these findings suggest the possibility of higher risks of more devastating tropical cyclones across the globe in a future greenhouse-warmed climate.