GFI/BCCR Seminar: Oceanic controls on ice shelf mass balance

Laurence Padman (Senior scientist, Earth & Space Research, USA):

Oceanic controls on ice shelf mass balance

Abstract
This talk will combine studies of satellite altimetry of ice-shelf height changes with numerical modeling to identify key processes by which ice shelves transfer changes in ocean temperature and circulation to mass loss from the grounded ice sheet. Overall, over the last two decades the loss of mass from Antarctic ice shelves has accelerated, indicating weakening of buttressing of grounded ice streams and glaciers. Most of this ice shelf mass loss is caused by accelerated basal melting, which changes in response to changes in oceanic forcing on time scales from tidal to interannual. Individual ice shelves respond very differently depending on the properties of water that flow under them, polynyas as a control on dense water production, strength of tidal currents, and geological constraints. When the ice dynamics of the adjacent grounded ice is also taken into account, changes in land-ice loss can vary dramatically from one Antarctic sector to another.