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The evolution of under-ice melt ponds, or double diffusion at the freezing point

Published online by Cambridge University Press:  29 March 2006

Seelye Martin  and
Peter Kauffman
Seelye Martin
Affiliation:
Department of Oceanography, University of Washington, Seattle
Peter Kauffman
Affiliation:
Department of Atmospheric Sciences, University of Washington, Seattle
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Abstract

In an experimental and theoretical study, we model a phenomenon observed in the summer Arctic, where a fresh-water layer at a temperature of 0°C floats both over a sea-water layer at its freezing point and under an ice layer. Our results show that the ice growth in this system takes place in three phases. First, because the fresh-water density decreases upon supercooling, the rapid diffusion of heat relative to salt from the fresh to the salt water causes a density inversion and thereby generates a high Rayleigh number convection in the fresh water. In this convection, supercooled water rises to the ice layer, where it nucleates into thin vertical interlocking ice crystals. When these sheets grow down to the interface, supercooling ceases. Second, the presence of the vertical ice sheets both constrains the temperature T and salinity s to lie on the freezing curve and allows them to diffuse in the vertical. In the interfacial region, the combination of these processes generates a lateral crystal growth, which continues until a horizontal ice sheet forms. Third, because of the T and s gradients in the sea water below this ice sheet, the horizontal sheet both migrates upwards and increases in thickness. From one-dimensional theoretical models of the first two phases, we find that the heat-transfer rates are 5–10 times those calculated for classic thermal diffusion.

Type
Research Article
Information
Journal of Fluid Mechanics , Volume 64 , Issue 3 , 8 July 1974 , pp. 507 - 528
Copyright
© 1974 Cambridge University Press

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References

Carslaw, H. S. & Jaeger, J. C. 1959 Conduction of Heat in Solids, 2nd edn. Oxford University Press.
Frank, F. C. 1950 Radially symmetric phase growth controlled by diffusion. Proc. Roy. Soc. A 201, 586–599.Google Scholar
Hanson, A. N. 1965 Studies of the mass budget of Arctic pack-ice floes. J. Glaciol. 5, 701–709.Google Scholar
Hodgman, C. D. (ed.) 1955 Handbook of Chemistry and Physics, 37th edn. Cleveland: Chemical Rubber Publishing Co.
Howard, L. N. 1966 Convection at high Rayleigh number. Proc. 11th Int. Congr. Appl. Mech., Munich (ed. H. Görtler), pp 1109–1115. Springer.
Kaufman, D. W. (ed.) 1960 Sodium Chloride. Reinhold.
Lyons, J. B., Savin, S. M. & Tamburi, A. J. 1971 Basement ice, Ward Hunt Ice Shelf, Ellesmere Island, Canada. J. Glaciol. 10, 93–100.Google Scholar
Mowbray, D. E. 1967 The use of schlieren and shadowgraph techniques in the study of flow patterns in density stratified fluids. J. Fluid Mech. 27, 595–608.Google Scholar
Nansen, F. 1997 Farthest North, vol. 1, pp. 457–459. New York: Harper & Brothers.
Perry, R. H., Chilton, C. H. & Kirkpatrick, S. D. (eds.) 1963 Chemical Engineers’ Handbook. McGraw-Hill.
Turner, J. S. 1973 Buoyancy Effects. in Fluids. Cambridge University Press.
Untersteiner, N. 1967 Natural desalination and equilibrium salinity profile of old sea ice. In Physics of Snow and Ice (ed. H. Oura), vol. 1, pp 569–577. Institute of Low Temperature Science, Hokkaido University, Japan.
Untersteiner, N. & Badgley, F. I. 1958 Preliminary results of thermal budget studies on Arctic pack ice during summer and autumn. In Arctic Sea Ice, pp. 85–92. Washington: U.S. Nat. Acad. Sci., Nat. Res. Counc. Publ. no. 598.
Veronis, G. 1970 The analogy between rotating and stratified flows. Ann. Rev. Fluid Mech. 2, 37–66.Google Scholar
Weeks, W. F. & Lofgren, G. 1967 The effective solute distribution coefficient during the freezing of NaCl solutions. In Physics of Snow and Ice (ed. H. Oura), vol. 1, pp 579–599. The Institute of Low Temperature Science, Hokkaido University, Japan.
Zubov, N. 1945 Arctic Ice (English trans.). U.S. Navy Electronics Laboratory, San Diego.