Ellipsometric study of the transition layer on the surface of an ice crystal

The physics of premelted ice and its geophysical consequences

“…6͒. Their simulation showed that the surface melting of the ͑0001͒ and ͑1010͒ faces differs in onset temperature and temperature dependence of melt layer thickness, consistent with the ellipsometry measurements ͑Beaglehole and Nason, 1980;Furukawa et al, 1987͒, discussed in Sec. IV.…”

“…The molecular-dynamics simulation found the onset of surface melting of the ͑0001͒ face began with high molecular rotational and translational mobility, at about −40°C. The discrepancy with experimental results ͑Beaglehole and Nason, 1980; Ocampo and Klinger, 1983;Furukawa et al, 1987;Mizuno and Hanafusa, 1987͒, which found that onset is much closer to T m , is usually ascribed to limitations of the pointcharge model of the water molecule which is used. Nevertheless, this study affords a detailed view of the interlinked changes of molecular orientation and diffusion attendant on surface melting of ice.…”

“…3 here, and Fig. 1 of Furukawa et al ͑1987͒; and see also Beaglehole and Nason ͑1980͔͒. Hence although different experimental methodologies probe different structural aspects of the surface, the variability among experimental data obtained using the same methodology on ice motivated an attempt to gain a basic understanding of the sensitivity of surface melting to the ubiquitous presence of electrolytic impurities ͑Wettlaufer, 1999a͒.…”

“…The general mechanism was proposed long ago, on the basis of qualitative arguments ͑Tammann, 1909; Stranski, 1942;Frenkel, 1946͒, but the principles of the modern theory were explicitly stated only many years later ͑Kristensen and Cotterill, 1977; Kuroda and Lacmann, 1982;Broughton and Gilmer, 1983a, 1983b, 1983c, 1984a, 1984bLipowsky and Speth, 1983;Furukawa et al, 1987;Nenow and Trayanov, 1989͒. Premelting is the general term for the phenomenon which can occur at three different classes of interface: surface melting between a solid and its vapor or gaseous atmosphere, interfacial melting in contact with foreign solid or liquid, and grain-boundary melting between crystals of the same material.…”

“…However, the surface melting of pure, wellordered ice surfaces at equilibrium in clean environments is limited to a span of only a few degrees below T m . Three experimental studies used optical methods ͑Beaglehole and Nason, 1980; Furukawa et al, 1987;: the first two, ellipsometry, and the third, reflectivity at the Brewster angle. Particular care was taken to assure crystal perfection in all three, but the two older studies were conducted in air-filled chambers.…”