A study finds that the ability of tall clouds to trap infrared radiation from the surface and lower atmosphere may play a role in the formation of intense tropical cyclones. While the prediction of the motion of tropical cyclones, including hurricanes and typhoons, has improved in recent decades, prediction of cyclone formation and intensification has not. James H. Ruppert and colleagues modeled the development of the Pacific Super Typhoon Haiyan from 2013 and the Atlantic Hurricane Maria from 2017 to investigate the role of infrared radiation in the transition from tropical disturbance to cyclone. The authors found that deep clouds trap infrared radiation from the Earth's surface and lower atmosphere, and the radiation strengthens the overturning circulation of the storm. The strengthening in turn promotes moisture saturation of the storm's core and accelerates its rotation through angular momentum convergence, shortening the time required for the storm to strengthen from a tropical depression into a typhoon or hurricane. According to the authors, the results suggest that trapped infrared radiation plays a significant role in tropical storm formation, and further research into this phenomenon could help improve the forecasting of destructive storms.
Article #20-13584: "The critical role of cloud-infrared radiation feedback in tropical cyclone development," by James H. Ruppert, Jr., Allison A. Wing, Xiaodong Tang, and Erika L. Duran.
MEDIA CONTACT: James H. Ruppert, Pennsylvania State University, University Park, PA; e-mail: james.ruppert@psu.edu
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Journal
Proceedings of the National Academy of Sciences