Tropical Cyclone Genesis: A Dynamician’s Point of View

Abstract

The paper focuses the route to the maturity of a cyclone as a twist process of the Hadley cell. The approach is qualified by a ``dynamician's viewpoint{''} since the aerologic mechanism of the cyclone genesis is replicated without the classical tools of the meteorological fluid framework. Indeed, we introduce a pure dynamical model of a 2D vertical rotor of an airparcel to emulate the Hadley cell. Twisted by an appropriate feedback to inject geophysical forcing, the simulation displays two stretched solenoid rolls with clockwise and anticlockwise paths representing the Hadley belts wrapping the Earth. When the forcing parameter is higher, computations simulate overlapped whirlwind funnels revealing strong similarities with the structure of cyclones, hurricanes, and typhoons described in the atmospheric science literature. We conjecture that ocean-atmosphere interactions separate and convert a ``slice{''} of the Hadley rotor into a fully tropical cyclone.