Sep 4, 2008

The increasing intensity of the strongest tropical cyclones

James B. Elsner, James P. Kossin, Thomas H. Jagger
  • Establishes there has been a 30-year trend showing an increase in Atlantic tropical cyclones strength related to an increase in ocean temperatures over the Atlantic Ocean and elsewhere
  • States trends in tropical cyclone intensity of less obvious over the rest of the tropics due to data limitations
  • The paper overcomes these limitations by examining trends in the maximum intensities that cyclones achieve during their lifetimes, estimated from homogeneous data derived from an archive of satellite records
  • Finds significant upward trends for wind speed quantiles above the 70th percentile, with trends as high as 0.3 plusminus 0.09 m s-1 yr-1 (s.e.) for the strongest cyclones
  • Notes separate upward trends in the estimated lifetime-maximum wind speeds of the very strongest tropical cyclones (99th percentile) over each ocean basin, with the largest increase at this quantile occurring over the North Atlantic, although not all basins show statistically significant increases
  • Results are qualitatively consistent with the hypothesis that as the seas warm, the ocean has more energy to convert to tropical cyclone wind