Lake ice ablation rates from permanently ice-covered Antarctic lakes

Abstract

In the McMurdo Dry Valleys of Antarctica, three large, permanently ice-covered, closedbasin lakes exist along the floor of Taylor Valley. Lake ice ablation (loss of ice mass) is calculated as the sum of sublimation and surface melt, and is the driver of ice-cover turnover in these systems. In Taylor Valley, both manual and automated lake ice ablation rates have been calculated from 2001 to 2011. Results indicate relatively consistent winter ablation of 0.07-0.21m (0.2-0.7mmw.e. d-1). Summer ablation of lake ice is more variable and ranges from 0.25 to 1.62m (5-31mmw.e. d-1) over an average 51 day period. Previous to this study, ablation rates have been cited as 0.35ma-1 in the dry valleys from sublimation modeling based on meteorological variables. We show that this value has significantly underestimated mean ablation and ice-cover turnover on the Taylor Valley lakes.