The National Center for Atmospheric Research (NCAR), in collaboration with PhD student Adam Herrington of the CEM group, have developed, tested and released a new dry-mass vertical coordinate spectral-element dynamical core for the Community Atmosphere Model, documented in the most recent issue of the Journal of Advances in Modeling Earth Systems (JAMES) and in preparation for the release of version 2.0 of the Community Earth System Model. The dry-mass vertical coordinate provides many advantages over the previous moist pressure based vertical coordinate; pressure levels are now invariant under phase change from the physical parameterizations, the explicit calculation of condensate loading important for high-resolution simulations and a comprehensive treatment of condensates and energy. Additional modifications to the hyper-viscosity operators, the vertical remapping algorithm, and a general streamlining of the code results in an improved kinetic energy spectrum and increased throughput on massively parallel systems.
