The Activeness of North Atlantic TC seasons Versus AMO Cycle

Discussion: Accumulated cyclone energy is a measure of the energy produced by a tropical cyclone measured on a 6-hourly basis and convenient for comparison of individual storms and seasonal activity. Well-known is the relationship between El Nino and La Nina to North Atlantic tropical cyclone season activity whereas El Nino suppresses activity and La Nina allows seasonal activity to flourish. As important is the ocean heat provided in the North Atlantic basin as measured by the Atlantic multi-decadal oscillation (AMO). The AMO cycle alternates between cool and warm phase every several decades. Currently, the warm cycle of the AMO is in-place. North Atlantic tropical cyclone seasons tend to be more active during the warm AMO cycle as demonstrated the past 20 years versus the considerably quieter period when AMO was in it’s cool cycle from the mid-to-late 1960’s to middle 1990’s.