Friday, 28 April 2006: 10:30 AM
Big Sur (Hyatt Regency Monterey)
Since 1995, the North Atlantic hurricane basin has been in an era of increased tropical cyclone activity as the result of a multidecadal-scale shift in certain climatic factors. The previous active era lasted from 1926 through 1970. Various measures of activity observed during the current active era are noticeably higher than for the previous one. There have even been suggestions that this difference in activity is the result of anthropogenic global warming, The issue addressed in this study is whether the differences in levels of activity between the earlier active era and the present one are real or simply a byproduct of improved observations.
It is well accepted that the quality of measures of overall activity is only reasonably acceptable starting with routine aircraft reconnaissance in 1944. The reliability of the data for the current active era, however, is dramatically different from that of the previous active era because the observational network has continually evolved from 1944 through the present. To show the impact of changes in observational methods, track data from the current active era will be “measured” under the constraints that existed between 1944 through 1970. Using this technique, the levels of activity for the two eras are seen to be much closer than from an unadjusted comparison.
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