An analytic model of the tropical cyclone outer size

Abstract There are simple conceptual models of tropical cyclone intensification and potential intensity. However, such a framework has been lacking to describe the evolution outer circulation. An analytic growth model size is derived from angular momentum equation. The fits full-physics idealized simulation. lifecycle composite best-track shows strong super-linear nature, which supports an exponential as predicted by model. climatology measured radius gale-force wind in North Atlantic Eastern Pacific during period 2004–2017, can be understood terms four factors model: initial size, duration, mean latitude, top-of-boundary-layer effective local inflow angle. All variables significantly different between two basins. observed lifetime maximum follows lognormal distribution, line with law proportionate effect this well global time constant approximately equal product Coriolis parameter angle above boundary layer. Further sensitivity experiments suggest that interannual variability largely driven variation duration.