NERSC Initiative for Scientific Exploration (NISE) 2010 Awards

High Resolution Climate Simulations with CCSM

Warren Washington, Jerry Meehl, and Tom Bettge, National Center for Atmospheric Research

Associated NERSC Project: Climate Change Simulations with CCSM: Moderate and High Resolution Studies (mp9), Principal Investigator: Warren Washington

The high resolution version of CCSM -- with a 0.5 degree atmospheric model coupled to a 1.0 degree ocean model as well as state-of-the-art sea ice and land surface scheme -- had previously encountered a numerically unstable polar night jet near the poles. The instability has now been treated, and the need exists to tune the model to a zero radiative balance to allow climate change simulations. The tuning will require approximately 40 simulated years. This model tuning exercise was not included in our original ERCAP proposal, and should be considered a supplemental research initiative. Then we intend to run the model for a 100 year control run with all constituents (e.g. greenhouse gases) held constant at 1850 values. That simulation will be followed by a historical climate simulation from 1850 to 2005 with time-evolving natural and anthropogenic forcings to test the model's ability to simulate a recently observed period in climate history. These simulations will provide the baseline comparison for future decadal prediction experiments with this model.