Le réchauffement climatique actuel influence-t-il l’activité des ouragans extrêmes de l’Atlantique Nord (1945-2018) ?

Abstract

This research concerning the North Atlantic Ocean is trying to establish a link between the extreme hurricanes (categories 4 and 5) activity and the global warming over the period 1945-2018. The hurricanes intensity has been estimated from 1945 to 1977 with the aircraft reconnaissances. These data come from the Hurdat database of National Hurricane Center in Miami. From 1978 to 2018, the intensity has been estimated with the Dvorak’s technique from the satellite pictures (archived from 1978). Three indicators have been studied: the extreme hurricanes number, their proportion in the category 1 to 5 hurricanes, and the absolute intensity of hurricanes for each decade. There is no trend in the number of extreme hurricanes over the period 1945-2018. The proportion of these hurricanes strongly increased with the positive phases of the Atlantic Multidecadal Oscillation (AMO), and deeply decreased in a negative phase. The proportion doubled during La Niña events compared to the El Niño events. There is no trend in the absolute intensity of hurricanes per decade. It is still complicated to detect a possible global warming signal in hurricanes data with the natural variations on multiple time-scales.

Keywords

• extreme hurricanes
• multidecadal oscillation
• El Niño
• La Niña
• global warming