We evaluate the climate and the computational performance of the Community Earth System Model, version 1, running with the new spectral element atmospheric dynamical core option. The spectral element method is configured to use a cubed-sphere grid, providing quasi-uniform resolution over the sphere, increased parallel scalability and removing the need for polar filters. It uses a fourth order accurate spatial discretization which locally conserves mass and total energy. Using the Atmosphere Model Intercomparison project protocol, we compare the results from the spectral-element dynamical core with those produced by the default finite-volume dynamical core and with observations, for both CAM4 and CAM5 physics.

The spectral element method also obtains unprecedented scalability on DOE Petascale computers, resulting in record setting performance at 1/4 and 1/8 degree configurations and the ability to effectively use O(200,000) cores on both the ORNL Cray XT6 and ANL IBM BG/P system.