C22B-02
GlacierMIP – A Model Intercomparison of Global-scale Glacier Mass-balance Models and Projections
Tuesday, 15 December 2015: 10:35
3007 (Moscone West)
Regine Hock1, Ben Marzeion2, Andrew Bliss1, Rianne H Giesen3, Yukiko Hirabayashi4, Matthias Huss5, Valentina Radic6 and Aimee Slangen7, (1)University of Alaska Fairbanks, Fairbanks, AK, United States, (2)University of Innsbruck, Innsbruck, Austria, (3)Institute for Marine and Atmospheric Research Utrecht, Utrecht, Netherlands, (4)The University of Tokyo, Tokyo, Japan, (5)ETH Swiss Federal Institute of Technology Zurich, Zurich, Switzerland, (6)University of British Columbia, Vancouver, BC, Canada, (7)CSIRO Hobart, Hobart, TAS, Australia
Abstract:
Modeling future glacier changes on a global scale is challenging due to scarcity of data for model initialization and calibration and biases in climate data in complex mountainous terrain. Hence, only few global-scale models have been published during the last ten years. Approaches to project global-scale mass balances broadly fall into three categories: (1) models based on simple extrapolation, (2) models based on mass balance sensitivities to temperature and precipitation changes, and (3) direct modeling of transient surface mass balance driven by climate data. Results from 8 to 15 Global Circulation Models indicate multi-model mean net mass losses of all glaciers on Earth (outside the ice sheets) between 66 mm and 242 mm sea-level equivalent by the end of this century. Amounts vary greatly depending on the choice of the forcing climate and emission scenario. Insufficiently constrained model parameters likely are an important reason for large differences found among previous studies even when forced by the same emission scenario, especially on regional scales. A new “Targeted Activity” under the Climate and Cryosphere (CliC) program, seeks to understand these differences, and for the first time provides a framework for a coordinated intercomparison of global-scale glacier mass change models with the ultimate goal to foster model improvements and reduce uncertainties in global glacier projections and associated contributions to sea-level rise.
