Journal of Climate 2012 ; e-View
Projected 21st century changes in temperature, precipitation and snow cover over North America in CCSM4
Results from a suite of ensembles of 21st century climate projections made using the Community Climate System Model Version 4 (CCSM4) are analyzed to document model bias, and to explore possible future changes in air temperature, precipitation and snow cover over North America. Large biases still exist in all analyzed fields in this version of the model, and the necessary assumption in future climate projections is therefore that the bias persists into the future, such that the differences in a field between two time periods are meaningful indications of potential changes. Projected temperature increases show strong regional patterns with spatial similarities for all the emissions scenarios considered, although there are considerable differences in the magnitude of the projected change. Projections indicate an increase in total precipitation over much of North America for all emissions scenarios, with the exception of the South-West US. All of North America except parts of Northern Canada show a projected decrease in snow cover over the 21st century.