How ice grows from premelting films and water droplets

Close to the triple point, surface of ice is covered by a thin liquid layer (so-called quasi-liquid layer) which crucially impacts growth and melting rates. Experimental probes cannot observe processes below this layer, classical models vapor deposition do not account for formation premelting films. Here, we develop mesoscopic model liquid-film mediated growth, identify various resulting regimes. At low saturation, freezing proceeds terrace spreading, but motion buried solid conveyed through outer liquid-vapor interface. higher saturations water droplets condense, large crater forms below, undetectably beneath droplet. Our approach general framework that naturally close three phase coexistence provides first principle theory may prove useful in geosciences.