Contact Information
- Department of Physics
- University of Toronto
60 St. George Street
Toronto, ON Canada
M5S 1A7
- Telephone: (416) 978-5213
- Fax: (416) 978-8905
- E-mail: amit@atmosp.physics.utoronto.ca
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Research
Abstract:
A high resolution primitive equations
(PE) model on the sphere is formulated in terms of: the
stream function (psi), the velocity potential (phi), T, q
(moisture) and p* (surface pressure). Where the vorticity
is del^2 psi and the divergence is del^2 phi. The PEs are
differentiated to give the divergence and vorticity
equations and are solved closely following the
semi-spectral method of Hoskins and Simmons (1975). The
model couples 2-dimensional finite element
sigma-levels by finite differences in the vertical,
coupled using the so-called T-scheme developed by Corby
et al. (1972) which formally conserves both mass and
energy. The methodology is similar to what is commonly
used by modern semi-spectral AGCMs. The semi-implicit
time-stepping scheme is used allowing a 30-90 minute
timestep, approximately two orders of magnitude longer
than what is possible with more conventional explicit
schemes. In the horizontal, Poisson and Helmholz
equations are solved on a regular icosahedral grid which
allows the use of fast multigrid methods developed by
Karpik and Peltier (1991) for 3-dimensions and
subsequently adapted to 2-dimensional shells by Stuhne
and Peltier (1996).
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