21st century estimates of mass loss rates from glaciers in the Gulf of Alaska and Canadian Archipelago using a GRACE constrained glacier model

Abstract. Ice mass loss rates from glaciers in the Gulf of Alaska and the Canadian Archipelago are expected to increase through the end of century in response to increasing temperatures. Here, we develop a new glacier model constrained by GRACE gravimetry observations for the period between 2002 and 2017. The high temporal and regional spatial resolution of GRACE mass balance estimates allows us to estimate regional glacier sensitivities to atmospheric changes, and account for higher order of glacier dynamics. We use our regionally constrained models to extrapolate future mass loss under different climate emission scenarios. Generally our 21st century sea level estimates are at the high end compared to other studies. We find that the Gulf of Alaska exhibits the highest mass loss rates between −79 to −112 Gt yr⁻¹ between 2006 and 2100 under different scenarios, and displays the highest sensitivity to the specific scenario (RCP 2.6/4.5/8.5). Our estimates for Baffin Island are significantly higher than prior work (−57 to −85 Gt yr⁻¹) and are comparable to projected mass loss rates from the Ellesmere region (−63 to −101 Gt yr⁻¹).