NCAR Release of CAM-SE in CESM2.0: A Reformulation of the Spectral Element Dynamical Core in Dry-Mass Vertical Coordinates With Comprehensive Treatment of Condensates and Energy

TitleNCAR Release of CAM-SE in CESM2.0: A Reformulation of the Spectral Element Dynamical Core in Dry-Mass Vertical Coordinates With Comprehensive Treatment of Condensates and Energy
Publication TypeJournal Article
Year of Publication2019
JournalJournal of Advances in Modeling Earth Systems
Volume10
Number7
Pages1537-1570
Date Published02/2019
Abstract / Summary

This paper provides comprehensive documentation of the new NCAR version of the spectral element (SE) dynamical core as part of the Community Earth System Model (CESM2.0) release. This version is a split from the previous version of SE, and resides in the CAM (Community Atmosphere Model) repository rather than being imported from the High‐Order Methods Modeling environment (HOMME) as an external code. The new version differs from previous releases of the SE dynamical core in several ways. Most notably the hybrid sigma vertical coordinate is based on dry air mass, the condensates are dynamically active in the thermodynamic and momentum equations (also referred to as condensate loading), and the continuous equations of motion conserve a more comprehensive total energy that includes condensates. The hyperviscosity operators and the vertical remapping algorithms have also been modified. The code base has been significantly reduced, sped up, and cleaned up. This paper also shows these computational advances. Several simulations demonstrate the features of the updated dynamical core.

URLhttp://dx.doi.org/10.1029/2017ms001257
DOI10.1029/2017ms001257
Journal: Journal of Advances in Modeling Earth Systems
Year of Publication: 2019
Volume: 10
Number: 7
Pages: 1537-1570
Date Published: 02/2019

This paper provides comprehensive documentation of the new NCAR version of the spectral element (SE) dynamical core as part of the Community Earth System Model (CESM2.0) release. This version is a split from the previous version of SE, and resides in the CAM (Community Atmosphere Model) repository rather than being imported from the High‐Order Methods Modeling environment (HOMME) as an external code. The new version differs from previous releases of the SE dynamical core in several ways. Most notably the hybrid sigma vertical coordinate is based on dry air mass, the condensates are dynamically active in the thermodynamic and momentum equations (also referred to as condensate loading), and the continuous equations of motion conserve a more comprehensive total energy that includes condensates. The hyperviscosity operators and the vertical remapping algorithms have also been modified. The code base has been significantly reduced, sped up, and cleaned up. This paper also shows these computational advances. Several simulations demonstrate the features of the updated dynamical core.

DOI: 10.1029/2017ms001257
Citation:
Lauritzen, P, R Nair, A Herrington, P Callaghan, S Goldhaber, J Dennis, J Bacmeister, et al.  2019.  "NCAR Release of CAM-SE in CESM2.0: A Reformulation of the Spectral Element Dynamical Core in Dry-Mass Vertical Coordinates With Comprehensive Treatment of Condensates and Energy."  Journal of Advances in Modeling Earth Systems 10(7): 1537-1570.  https://doi.org/10.1029/2017ms001257.