image: Uprooted trees in Hallasan National Park, South Korea, after Typhoon Bolaven struck in August 2012. view more
Credit: Image courtesy of Jan Altman.
Researchers report evidence of a poleward shift in tropical cyclone (TC) activity. The long-term variability of TC activity is unclear, largely due to discrepancies among datasets and brief instrumental records. Jan Altman and colleagues estimated the long-term variability of TC activity in coastal northeast Asia based on forest canopy disturbance rates recorded in tree rings. As latitude increased between 33°N and 45°N, the frequency of canopy disturbance in trees within the first 15 years of life decreased, whereas the frequency of canopy disturbance after the 15th year increased, reflecting decreasing TC activity from south to north. The frequency of trees experiencing canopy disturbance between the 15th and 50th years increased with latitude more steeply for trees whose first ring appeared in or after 1920, compared with older trees. Consequently, the younger trees were significantly more likely to experience canopy disturbance at high latitudes. The frequency of experiencing canopy disturbance after the 50th year of life was much lower for post-1920 trees than for pre-1920 trees. The results suggest increased TC activity at northern sites after 1920. Regions currently at the edge of TC impact may experience increasing threat in the future, according to the authors.
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Article #18-08979: "Poleward migration of the destructive effects of tropical cyclones during the 20th century," by Jan Altman et al.
MEDIA CONTACT: Jan Altman, Institute of Botany of the Czech Academy of Sciences, Pr?honice, CZECH REPUBLIC, and Swiss Federal Institute for Forest, Snow, and Landscape Research, Birmensdorf, SWITZERLAND; e-mail: altman.jan@gmail.com
Journal
Proceedings of the National Academy of Sciences