Tropical Cyclones Intensifying Due to Warming Atmosphere

Science Breakthrough

Using computational resources at NERSC, researchers from Pacific Northwest National Laboratory, Lawrence Berkeley National Laboratory (Berkeley Lab), and partnering institutions have gained a better understanding of how tropical cyclones taking place near coastal regions have intensified over time, the likely causes of the change, and what the future might hold according to climate models. Their work was published in Earth’s Future in May.

Science Background

Tropical cyclones that intensify near a coastline are among the most destructive natural hazards on Earth. Previous research helped scientists gain an understanding of key contributors to these storms, as well as their impacts, but few studies had looked at the phenomenon at a global scale. In this study, the researchers considered the large-scale environment to gain new insights that may help coastal communities prepare for a future with more frequent, more intense storms due to a warming climate.

Science Breakdown

The team used the Perlmutter system at NERSC to analyze simulations using the Coupled Model Intercomparison Project phase 6 (CMIP6) climate model, looking at simulations of both current and future climates.

They found that the average intensification rate of tropical cyclones has increased significantly over the period 1979–2020 near global coastal regions. According to the simulations, the change is due primarily to increases in relative humidity and decreases in vertical wind shear – that is, changes in wind speed or direction over a short distance. High-resolution climate models suggest that the increase in intensification is likely to continue in the future as vertical wind shear continues to decrease. To better understand wind shear projections, the researchers performed a set of idealized numerical sensitivity experiments with a Stationary Wave Model, a model with simplified physics that allows researchers to tease out the various processes that play a role in the climate system. By capturing and isolating these processes, they found that enhanced warming in the upper-troposphere and changing patterns of ocean warming are likely responsible for the intensification they had observed.

Research Lead

Karthik Balaguru, Pacific Northwest National Laboratory

Co-authors

C. Chang, L.R. Leung, G.R. Foltz, S.R. Hagos, M.F. Wehner, J.P. Kossin, M. Ting, W. Xu

Publication

Balaguru, K., Chang, C.-C., Leung, L. R., Foltz, G. R., Hagos, S. M., Wehner, M. F., et al. (2024). A global increase in nearshore tropical cyclone intensification. Earth's Future, 12, e2023EF004230. https://doi.org/10.1029/2023EF004230

Funding

DOE Office of Science, Office of Biological and Environmental Research

User Facilities

NERSC