THE ATLANTIC MERIDIONAL MODE AND HURRICANE ACTIVITY

The Atlantic Meridional Mode (AMM) is the dominant source of coupled ocean / atmosphere variability in the tropical Atlantic. The AMM, a dynamical “mode” of variability intrinsic to the coupled ocean / atmosphere system, has been shown to be strongly related to hurricane activity in the tropical Atlantic. This relationship emerges due to the AMM's influence on a number of large-scale conditions that all cooperate in generating environmental conditions that favor hurricane activity. These relationships offer a different framework, beyond traditional thermodynamic arguments, for understanding relationships between hurricane activity and climate in the historical record.

Current efforts at understanding the AMM's role in linking hurricane activity with climate variations include relating the AMM to decadal variations in the Atlantic (the AMM provides a physical mechanism to link the Atlantic Multi-decadal Oscillation with hurricane activity); exploring the seasonal predictability of the AMM, and by extension, hurricane activity; and re-examining the hypothesis that hurricane activity will increase in the future as sea surface temperature increases.

A brief review of the structure and dynamics of the AMM, its relationships with hurricane activity, and ongoing research on AMM / hurricane relationships, will be presented.