This paper explores the role of air-sea interactions in the development and maintenance of tropical cyclones, particularly focusing on the hypothesis that latent heat from the sea is essential for their intensification and maintenance. The authors argue that tropical cyclones can be maintained in a steady state without conditional instability of the ambient air, relying instead on self-induced anomalous fluxes of moist enthalpy from the sea surface. They develop a highly idealized nonlinear axisymmetric model to demonstrate that intense steady-state storms can be simulated without the need for preexisting conditional instability. The model assumes inviscid and thermodynamically reversible flow above the boundary layer, hydrostatic and gradient wind balance, and slantwise neutrality to slantwise moist convection. The paper derives analytic relationships between wind and saturated entropy fields, and shows that the pressure deficit in the storm center is influenced by the increase in surface relative humidity. The model also predicts that the minimum central pressure attainable by tropical cyclones depends on sea surface temperature and outflow temperature. The authors conclude that the observed absence of tropical cyclone formation when sea surface temperatures are below 26°C is due to the lack of deep conditional instability or neutrality over these regions.This paper explores the role of air-sea interactions in the development and maintenance of tropical cyclones, particularly focusing on the hypothesis that latent heat from the sea is essential for their intensification and maintenance. The authors argue that tropical cyclones can be maintained in a steady state without conditional instability of the ambient air, relying instead on self-induced anomalous fluxes of moist enthalpy from the sea surface. They develop a highly idealized nonlinear axisymmetric model to demonstrate that intense steady-state storms can be simulated without the need for preexisting conditional instability. The model assumes inviscid and thermodynamically reversible flow above the boundary layer, hydrostatic and gradient wind balance, and slantwise neutrality to slantwise moist convection. The paper derives analytic relationships between wind and saturated entropy fields, and shows that the pressure deficit in the storm center is influenced by the increase in surface relative humidity. The model also predicts that the minimum central pressure attainable by tropical cyclones depends on sea surface temperature and outflow temperature. The authors conclude that the observed absence of tropical cyclone formation when sea surface temperatures are below 26°C is due to the lack of deep conditional instability or neutrality over these regions.