Accuracy analysis of a spectral element atmospheric model using a fully implicit solution framework

Journal Article · Fri Jan 01 04:00:00 EST 2010 · Monthly Weather Review

DOI:https://doi.org/10.1175/2010MWR3288.1· OSTI ID:984765

Evans, Katherine J ^[1]; Taylor, Mark ^[2]; Drake, John B ^[1]

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1. ORNL
2. Sandia National Laboratories (SNL)

A fully implicit (FI) time integration method has been implemented into a spectral finite element shallow water equation model on a sphere, and it is compared to existing fully explicit leapfrog and semi-implicit methods for a suite of test cases. This experiment is designed to determine the time step sizes that minimize simulation time while maintaining sufficient accuracy for these problems. For test cases without an analytical solution from which to compare, it is demonstrated that time step sizes 30 to 60 times larger than the gravity wave stability limits and 6 to 20 times larger than the advective scale stability limits are possible using the FI method without a loss in accuracy, depending on the problem being solved. For a steady-state test case, the FI method produces error within machine accuracy limits as with existing methods, but using an arbitrarily large time step size.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF); Oak Ridge National Laboratory (ORNL); Center for Computational Sciences
• Sponsoring Organization: DOE Office of Science; ORNL LDRD Director's R&D; ORNL work for others
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 984765
• Journal Information: Monthly Weather Review, Journal Name: Monthly Weather Review Journal Issue: 8 Vol. 138; ISSN MWREAB; ISSN 0027-0644
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
ACCURACY
ANALYTICAL SOLUTION
GRAVITY WAVES
SIMULATION
STABILITY
WATER
atmospheric climate model
fully implicit
temporal accuracy