Wave energy accumulation and tropical cyclone genesis

Interactions of easterly waves with the background flow can result in a reduction in the longitudinal and vertical scale of the waves and a regional accumulation of wave energy; thereby increasing relative vorticity and the likelihood of tropical cyclone (TC) genesis near the wave axis.

The importance of wave energy accumulation for TC genesis is explored using an idealized modeling framework using the Weather Research and Forecast (WRF) model. The idealized environment is constructed to represent the summertime climate over the tropical North Atlantic; that is, easterly waves propagating through a spatially varying background environment. First, the important magnitudes and scales of motion for TC genesis are determined followed by an assessment of the relative importance of wave energy accumulation for TC genesis compared to other potentially important processes including diabatic heating from deep convection. Finally, the implications of wave energy accumulation for temporal and spatial clustering of TCs will be discussed together with its possible role as a physical mechanism underlying known statistical relationships between TCs and large-scale tropical modes of variability.