Ice formation in the Mertz Glacier polynya, East Antarctica, during winter

Abstract
During August 1999, detailed data were collected in the Mertz Glacier polynya along the coast of Antarctica on the drift of newly forming ice tracked with drifting buoys and the ice thickness in the vicinity of the buoys over time. Using these measurements, we estimate the ice-growth rate and the processes which are important in the early stages of ice formation. We find that although there is rapid frazil formation in the open-water areas near the coast and Mertz Glacier Tongue, this frazil ice can take several days to consolidate. A period of warmer weather, when temperatures reached as high as 0°C, delayed the consolidation of the frazil for > 4.5 days. The undeformed new-ice growth rate averaged about 4 cm d-1 for the first 5 days of formation. Ridging and rafting doubled the total growth rate to an average of 8 cm d-1. Blowing and falling snow was incorporated into the surface of the newly forming ice, with 16 of 22 ice cores having some snow in the top few centimeters.