The response of the Greenland ice sheet in the 21st century obtained from an ice-sheet model coupled interactively with an AOGCM

• Main Authors: Huybrechts, Philippe, Janssens, I., Poncin, C., Fichefet, T.
• Format: Conference Object
• Language: unknown
• Published: 2003
• Subjects: Greenland; Ice Sheet; North Atlantic
• Online Access: https://epic.awi.de/id/eprint/6948/; https://hdl.handle.net/10013/epic.17498

Results are presented from a climate change simulation obtained from an atmosphereoceangeneral circulation model coupled with a three-dimensional model of the Greenlandice sheet. The experiment covers the period 1970-2100 and is driven by the midrangeIPCC SRES B2 scenario. The Greenland model is a high-resolution (20 km)thermomechanical model that includes a visco-elastic solid Earth model. The meltand-runoff model is based on the positive-degree day method and includes meltwaterretention in the snowpack and the formation of superimposed ice. The AOGCM is acoarse resolution model without flux correction based on the LMD 5.3 atmosphericmodel coupled with a primitive-equation, free-surface oceanic component incorporatingsea-ice (CLIO). In the coupling procedure, the ice-sheet model receives temperatureand precipitation changes from the AOGCM in anomaly mode and passes theannual spatial and temporal distribution of the different fresh water flux componentsback into the ocean. In the experiment, average Greenland temperature rises by about4C by 2080, but cools abruptly through a weakening of the North Atlantic thermohalinecirculation to near-present values by the end of the 21st century. This behaviour iscaused by the increased meltwater flux from the ice sheet itself. The total fresh waterflux approximately doubles over the first 100 years due to increased runoff from theice sheet and the ice-free land, but the calving rate is found to decrease by 25% overthe same period. The ice sheet shrinks equivalent to about 5.5 cm of sea-level rise.