How mountains help shape the tracks of tropical cyclones

Yi-Hsuan Huang, Chun-Chieh Wu, and Yuqing Wang, The influence of island topography on typhoon track deflection, Monthly Weather Review, doi:10.1175/2011MWR3560.1

Both observational and numerical studies have shown that the highly mountainous island of Taiwan can deflect approaching cyclones. Just before it brushed the northern tip of Taiwan in 2007, Typhoon Krosa arced to the left and moved in a cyclonic loop for several hours. Krosa’s track was successfully reproduced with simulations from a high-resolution model (3 kilometers, or 1.9 miles), while runs carried out at coarser resolution (9 km, or 5.6 mi) were less successful. These experiments, plus an idealized set of simulations, show that the interactions between intense typhoons and high terrain, including winds strongly channeled by mountains, can be realistically captured only at finer resolutions.

NATIONAL TAIWAN UNIVERSITY • UNIVERSITY OF HAWAII AT MANOA