A universal, broad‐environment energy conversion signature of explosive cyclones

Abstract

This study presents the first analysis of the Lorenz energetics associated with a global climatology of explosive cyclones. Energy budgets of the large‐scale environment are calculated for 32 year climatologies (1980–2011) of explosive cyclones within four of the most active regions in the world: the Northwest Pacific, the North Atlantic, the Southwest Pacific, and the South Atlantic. A robust signature in the Lorenz energy cycle is observed; anomalous energy conversions commence 48 h before explosive cyclone development and remain strong (i.e., significantly above background noise) for 120 h. Remarkably, the calculated signature of energy conversion is virtually identical for all four geographical regions. While the conversions imply a classic baroclinic growth cycle, they are not seen in regular cyclones that undergo a deepening of less than half that exhibited by explosive cyclones. This finding opens a new avenue of exploration of explosive storm behavior based on the large‐scale environment.