Building a Next-Generation Community Ice Sheet Model

• Main Author: Jesse Johnson
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2008
• Subjects: Antarctic; Greenland; Antarc*; Ice Sheet; Ice Shelves; Iceberg*
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.466.8812; http://oceans11.lanl.gov/trac/CISM/raw-attachment/wiki/WorkshopReport/CISM_Workshop_Report.pdf

create a detailed plan (including commitments from individual researchers) for developing, testing, and applying a Community Ice Sheet Model (CISM). This model will be used to predict 21st century sea-level rise resulting from the retreat of the Greenland and Antarctic ice sheets. CISM will be freely available to the glaciology and climate modeling communities and will serve as the ice-sheet component of the Community Climate System Model (CCSM), a major contributor to the IPCC assessment reports. Because of the short time scale for including ice-sheet forecasts in the next IPCC assessment, participants prioritized model improvements according to their importance for sea-level prediction. The following improvements were deemed critical: • A higher-order flow model, with a unified treatment of vertical shear stresses and horizontal-plane (lateral shear and longitudinal normal) stresses • Improved models of basal sliding over hard and soft beds, including explicit treatment of surface, englacial, and subglacial hydrology • A well-validated parameterization of melting and refreezing beneath ice shelves • An accurate, semi-empirical law for iceberg calving