Abstract
The Community Atmosphere Model (CAM) version 5 includes a
spectral element dynamical core option from NCAR's High-Order Method Modeling
Environment. It is a continuous Galerkin spectral finite element
method designed for fully unstructured quadrilateral meshes. The
current configurations in CAM are based on the cubed-sphere grid. The
main motivation for including a spectral element dynamical core is to
improve the scalability of CAM by allowing quasi-uniform grids for the
sphere that do not require polar filters. In addition, the approach
provides other state-of-the-art capabilities such as improved
conservation properties. Spectral elements are used for the
horizontal discretization, while most other aspects of the dynamical
core are a hybrid of well tested techniques from CAM's finite volume
and global spectral dynamical core options. Here we first give a
overview of the spectral element dynamical core as used in CAM. We
then give scalability and performance results from CAM running with
three different dynamical core options within the Community Earth
System Model, using a pre-industrial time-slice configuration. We
focus on high resolution simulations of 1/4 degree, 1/8 degree, and
T340 spectral truncation.
