05/01/2006
Mountain Snow Pack Projected to Decline
Summary
A global climate model with an embedded downscaling scheme predicts that regional mean mountain snow pack would decline by up to 50-80% for many regions of the globe over the next century in response to a scenario of increasing greenhouse gas concentrations in the atmosphere. Previous studies with regional climate models have suggested similar reductions for selected regions and decades in the 21st century. Now, for the first time, a global climate model provides global estimates of snowmelt with 5 km spatial resolution for the period 1980-2100. Researchers at the Pacific Northwest National Laboratory added a physically-based downscaling scheme to the Community Climate System Model (CCSM), and used the model to simulate the climate for the period 1980-2100 using an Intergovernmental Panel on Climate Change scenario of increasing greenhouse gas concentrations during this period as a climate forcing. The downscaling scheme used was fully interactive with the atmosphere and land components of the CCSM and provided global 5 km spatial resolution for any climate variable. Snow pack is most sensitive to spatial resolution because of its dependence on both temperature and precipitation, both of which also depend on surface elevation.
References
Ghan, S. J., and T. Shippert. 2006. “Physically-based global downscaling: Climate change projections for a full century,” J. Climate 19 1589 1604.