A hypothesis for the amplification of certain atmospheric circulations, including tropical cyclones, polar lows, and the Madden– Julian oscillation. The mechanism involves a positive feedback between the circulation and heat fluxes from the sea surface, with stronger circulation giving rise to larger surface fluxes of heat, which are then quickly redistributed aloft by convection, in turn strengthening the circulation. In this theory, emphasis is placed on the surface fluxes as the principal rate-limiting process; convection serves only to redistribute heat. This can be contrasted with conditional instability of the second kind (CISK), in which circulations amplify through their interaction with the convection itself.