Putting the brakes on the hurricane heat engine

Emanuel replies: Jonathan Katz advances the intriguing idea that hurricanes could be mitigated by attacking the air–sea interface, through which enthalpy must flow to power the storms. The notion that the fluxes could be reduced by applying a surfactant was first proposed, to the best of my knowledge, by Robert Simpson and Joanne Simpson. ¹ But the idea remained on the table for decades and has yet to be adequately tested. A few years ago, Moshe Alamaro and I did experiment with surfactants using a wind–wave flume, a laboratory apparatus in which air is moved at high speed over a water surface. We confirmed that at low wind speeds, surfactants dramatically reduced surface enthalpy flux. But at high speeds, the surfactant layer disintegrated and showed no measurable effect on the fluxes. We were only able to experiment with a limited number of candidate substances, but, given the stakes, this idea is surely worth deeper exploration.