Subaqueous melting of Store Glacier, west Greenland from three-dimensional, high-resolution numerical modeling and ocean observations

摘要

We present three-dimensional, high-resolution simulations of ice melting at the calving face of Store Glacier, a tidewater glacier in West Greenland, using the Massachusetts Institute of Technology general circulation model. We compare the simulated ice melt with an estimate derived from oceanographic data. The simulations show turbulent upwelling and spreading of the freshwater-laden plume along the ice face and the vigorous melting of ice at rates of meters per day. The simulated August 2010 melt rate of 2.0±0.3 m/d is within uncertainties of the melt rate of 3.0±1.0 m/d calculated from oceanographic data. Melting is greatest at depth, above the subglacial channels, causing glacier undercutting. Melt rates increase proportionally to thermal forcing raised to the power of 1.2-1.6 and to subglacial water flux raised to the power of 0.5-0.9. Therefore, in a warmer climate, Store Glacier melting by ocean may increase from both increased ocean temperature and subglacial discharge. Key Points Simulated melt agrees with estimates from a hydrographic survey of the glacier. With more runoff, glaciers will melt faster at constant ocean temperature.