A Spectral Element Eulerian-Lagrangian Atmospheric Model (SEELAM)
Abstract
A new dynamical core for numerical weather prediction (NWP) based on the spectral element Eulerian-Lagrangian (SEEL) method is presented. This paper represents a departure from previously published work on solving the atmospheric equations in that the horizontal operators are all written, discretized, and solved in 3D Cartesian space. The advantages of this new methodology are: the pole singularity which plagues all gridpoint methods disappears, the horizontal operators can be approximated by local high-order elements, the Eulerian-Lagrangian formulation permits extremely large time-steps, and the fully-implicit Eulerian-Lagrangian formulation only requires the inversion of a 2D Helmholtz operator. In order to validate the SEELAM model, results for four test cases are shown. These are: the Rossby-Haurwitz waves number 1 and 4, and the Jablonowski-Williamson balanced initial state and baroclinic instability tests. Comparisons with four well-established operational models show that SEELAM is as accurate as spectral transform models.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 2008
- Accession Number
- ADA486691
Entities
People
- Francis X. Giraldo
Organizations
- United States Naval Research Laboratory