The Time-Dependent Evolution of the Tropical Cyclone Low-Level Wind Field

The low-level wind field in a tropical cyclone is critical both to the energetics of the system as a whole and to the risk posed to life and property by wind, surge, and rain at landfall. Recent work developed a theoretical model for the low-level wind field that takes as free parameters intensity, outer size, and rotation rate. Modeling studies have identified an inverse scaling of outer size with rotation rate at equilibrium in simulations with uniform rotation. However, such a dependence is not found in observations, suggesting that non-equilibrium effects are at play in nature. Here we test the time-dependent variation of storm size and structure with latitude in a hierarchy of idealized numerical simulation experiments from axisymmetric to global aquaplanet simulations with both uniform and Earth-like rotation. We then compare our results with results from equilibrium simulations to assess the extent to which equilibrium dynamics can explain variation in real storm size in nature.