20 February 2019

Understanding How Changes in African Dust Might Affect Future Hurricanes in a State-of-the-Art Climate Model

Science

The destructive potential of North Atlantic hurricane seasons can be affected by dust emission from Africa. As stormy clouds, or hurricane “seeds,” develop over the tropical North Atlantic Ocean, the dust blown over by the wind from Africa is thought to contribute to dry and stable air, which can make it harder for these “seeds” to develop into stronger storms or hurricanes. In a future warming climate, African dust emission is projected to decrease due to changes in regional wind patterns. This is one of the less understood factors adding to the uncertainty of North Atlantic hurricane activity in the future. In this study, we look at how the impact of African dust on hurricanes shows up in a climate model with sufficient resolution to represent hurricanes.

Impact

Increased understanding of how dust impacts hurricanes in high-resolution climate models has implications for future projections and risk associated with resulting changes in hurricane activity. This work demonstrates that high-resolution climate models with appropriate aerosol models offer a critical tool for exploring hurricane-dust interactions on decadal time scales. The results also call for future research focusing on untangling the mechanisms of such interactions.

Summary

In this study, we conducted two sets of experiments using the Community Atmosphere Model at a global horizontal grid spacing of 28 km. Following the control experiment (1980–2012) with standard amounts of dust, a low dust experiment is completed where the amount of airborne dust in the model is reduced over the same historical period. In this low dust simulation, tropical cyclone frequency averaged over all the world’s ocean basins increases. In the North Atlantic ocean basin, which is the most directly affected by African dust emission, storms become more frequent, stronger and longer lived, all contributing to their increased potential for destruction. This study contributes to understanding how dust influences tropical cyclone formation and development in climate models, which will help us understand and prepare for the potential changes in hurricanes of the coming decades.

Contact
Kevin A. Reed
Stony Brook University
Publications
Reed, KA, JT Bacmeister, JA Huff, X Wu, SC Bates, and NA Rosenbloom.  2019.  "Exploring the Impact of Dust on North Atlantic Hurricanes in a High-Resolution Climate Model."  Geophysical Research Letters 46(2): 1105-1112.  https://doi.org/10.1029/2018gl080642.