Sharp rise in hurricane and cyclone count during the last century

摘要

In the present analysis, we study the North Atlantic hurricanes and the tropical cyclones over the Atlantic, attempting to statistically contribute to the study of the recently observed rapid shifts of sea surface temperature anomalies (SSTa) and hurricane activity. Indeed, the annual values of hurricane count (HC), during 1900-2012, seem to show two abrupt increasing events which temporally coincide with the SST shifts. Moreover, the superposition of a staircase function on the Southern Oscillation Index (SOI) after removing the effect of the Pacific Decadal Oscillation (PDO) and the quasi-biennial oscillation (QBO) provides a good fit to the observed HC values. In addition, the annual values of the tropical cyclone count (TCC), during 1900-2006, analyzed with the same procedure as that of HC exhibit similar features to those of the HC values, revealing abrupt shifts in the same years. Furthermore, the application of two shift detection statistical methods determines more accurately the intervals where the shifts occur for each of the three parameters (SSTa, HC, and TCC). Nevertheless, the undersampling of hurricane numbers during early and mid-twentieth century due to the observing capabilities may have contributed to the first rapid shift in hurricane activity.