codes for TC_oscillations
Theoretical descriptions of tropical cyclone intensification assume convective motions to keep the atmosphere in neutrally stable conditions. Under those circumstances, only surface heat fluxes matter for the intensification of the cyclone up to a mature phase in which the energy input at the air-sea interface is balanced by frictional energy dissipation. However, simulations performed with a cloud-resolving model in idealized settings show a different picture. The initial intensification is consistent with the theoretical expectations, but the tropical cyclone then undergoes strong oscillations. This behavior is linked to interactions between the cyclone intensity and the stability of the air column. Convective heating warms the middle and upper parts of the cyclone, further warmed by mixing with low stratospheric air, which stabilizes the air column. This limits the upward motion of the near-surface air and the latent heat release and eventually results in a weakening of its intensity. Subsequently, during the intensity decay phase, the middle and upper atmosphere cools, mainly due to cold air being brought in from the surroundings, and this process favors again convection and so a new intensification phase.