How ice grows from premelting films and water droplets

Abstract

Close to the triple point, the surface of ice is covered by a thin liquid layer (so-called quasi-liquid layer) which crucially impacts growth and melting rates. Experimental probes cannotobserve the growth processes below this layer, and classical models of growth by vapordeposition do not account for the formation of premeltingfilms. Here, we develop a meso-scopic model of liquid-film mediated ice growth, and identify the various resulting growthregimes. At low saturation, freezing proceeds by terrace spreading, but the motion of theburied solid is conveyed through the liquid to the outer liquid–vapor interface. At highersaturations water droplets condense, a large crater forms below, and freezing proceedsundetectably beneath the droplet. Our approach is a general framework that naturally models freezing close to three phase coexistence and provides afirst principle theory of ice growthand melting which may prove useful in the geosciences