Plenary Talk 1

Abstract

We have recently discovered the photomolecular effect: photons cleave off water clusters from the air-water interface. We use ~20 different experiments to demonstrate the existence of this effect at a single water-air interface and in porous hydrogels. In this talk, I will first summarize the key experimental evidence, and then present progress in modeling the photomolecular effect. We redrived a set of modified boundary conditions for the Maxwell equations using Feibelman parameters developed for the surface photoelectric effect, based on which we derive the surface absorptance due to the photomolecular effect and show that it leads to reasonable agreements with the angle and polarization dependence measured in the photomolecular effect experiments. We then moved on to access the effect of the photomolecular effect on cloud absorptance by modifying the Mie theory and solving the equation of radiative transfer. Our results suggest that the photomolecular effect underpins an over 70 years old puzzle: measurements have repeatedly led to much higher clouds absorptance for solar radiation than what theory can predict. Our studies suggest that the photomolecular effect should happen widely in nature, from clouds to fogs, ocean to soil surfaces, plant transpiration, and can also lead to new applications in energy and clear water.