Cryospheric and Polar Processes Seminar: Matthew Hoffman

Validation of the Dynamic Response of Ice Sheet Models to Changes in Outlet Glacier Discharge

by Dr. Matthew Hoffman - Scientist, Climate, Ocean, & Sea Ice Modeling (COSIM) Group, Los Alamos National Laboratory

Although ice sheet models are used for sea level rise projections, the degree to which these models have been validated by observations is fairly limited, due in part to the limited duration of the satellite observation era and the long adjustment time scales of ice sheets. Here we describe a validation framework for the Greenland Ice Sheet applied to the Community Ice Sheet Model by forcing the model annually with flux anomalies at the major outlet glaciers (observed from Landsat/ASTER/OIB) and surface mass balance (calculated from RACMO2) for the period 1991-2012. The ice sheet model output is compared to ice surface elevation observations from ICESat and ice sheet mass observations from GRACE. While this testbed is still in development, early results show promise for assessing the performance of different model configurations.