Future projections of Antarctic ice shelf melting and global sea level rise

Abstract

With global warming, sea level rise rapidly and various kinds of natural catastrophes occur more frequently, especially hydrological, meteorological events such as tropical cyclone, flooding. Therefore, improved sea-level projections are required for global and regional adaptation strategies. Recently, a series of studies pointed out the collapse of the Antarctic ice sheet is accelerating and may have already passed a tipping point based on new observations and simulations. Antarctica is the main driver of the risk of really high sea level rise, so we really need to understand what's happening there. Even though better future projection of global climate change requires the rigorous understanding on the interactions in cryosphere, the technology level of the ice sheet modelling is rather limited for this region. Under these circumstances, new modeling activity in KOPRI is initiated to predict the tipping point for the irreversible Antarctic melting and unstoppable sea level rise. The main objective is to reduce uncertainties and enhance predictability of future sea level rise by improving the ice sheet model by intensifying our understanding on the ice sheet processes and dynamics based on field observations. At first, we tested the idealized scenarios of the oceanic forcings including floating ice melting and ice front retreat for future projections targeting the Drygalski Ice Tongue and David Glacier, East Antarctica. The 2-dimensional (2-D) shallow shelf approximation model (MacAyeal, 1989), which is implemented in the Ice Sheet System model (ISSM) (Larour et al., 2012) is used. Sensitivity experiments are conducted to verify the significant differences induced by changes in model. A series of projected simulations are compared to explore the role of forcing scenarios on the grounding line migration, surface mass balance and sea level contribution.