For the numerical solution, the SIMPLER/ADREA algorithm is used, based on the SIMPLER algorithm given in Patankar, (1980). The mixture mass conservation equation is turned to a full pressure (Poisson) including the transient term. Pressure correc-tion is avoided. Under-relaxation factors are also avoided.
spectral
spectral
2nd or 4th order finite differencing, or else Zalesak's scheme (monotonic)
id.
Second-order finite differences
Second-order finite differences
grid point method with finite difference approximation
grid point method with finite difference approximation
grid point method with finite difference approximation
grid point method with finite difference approximation
Second-order finite differences
Second-order finite differences
Second-order centered finite differences
Second-order centered finite differences
McCormack scheme (predictor/corrector) with alternating upstream/downstream discretization
Smolarkiewicz-Scheme
vertical diffusion terms semi-implicit; implicit pressure gradient terms by solving a Helmholtz-Equation with preconditioned conjugate gradient method
on icosahedral grid following Baumgardner (1983)
on icosahedral grid following Baumgardner (1983)
grid point method with finite difference approximation
grid point method with finite difference approximation
grid point method with finite difference approximation
grid point method with finite difference approximation
centered differences
centered differences
centered differences or (W)ENO
upstream or (W)ENO
values interpolated to other grid points by linear or higher order interpolation
The discretization of the space derivatives is by finite differences on a grid staggered in the three dimensions. This arrangement is known as a Arakawa C-grid for the horizontal and a Tokioka B-grid for the vertical. The center of the elementary matrix is the pressure surrounded horizontally by U and V, and surrounded vertically by w, W and the scalars.
see MM5 online tutorial
see MM5 online tutorial
The conservation equations for mass, momentum, are solved.
The conservation equations for scalar quantities as potential temperature, turbulent kinetic energy and specific humidity are solved.
Fast elliptic solver, which is based on fast Fourier analysis in both horizontal directions and Gaussian elimination in the vertical direction.
please refer to the techical reference.
Includes thermal energy, water vapour, turbulent kinetic energy and polutant concentrations. For more details, please refer to the technical reference.
finite volume, cell centered
idem
possibility to use different cell elements (tetrahedral, hexahedral...)
centered differences or (W)ENO
upstream or (W)ENO
centered differences; values interpolated to other grid points by linear or higher order interpolation
please check te on-line tutorial
please check te on-line tutorial
please check the on-line tutorial
please check the on-line tutorial
For time integration, time-splitting scheme is used on fast terms, forward step is used for diffusion and microphysics. Some radiation and
cumulus options use a constant tendency over periods of many model timesteps and are only
recalculated every 30 minutes or so.
2nd order or 4th centred advection scheme
2nd order or 4th positive definite advection scheme (PPM)
See:
http://www.atmet.com/html/docs/rams/rams_techman.pdf
See:
http://www.atmet.com/html/docs/rams/rams_techman.pdf
See:
http://www.atmet.com/html/docs/rams/rams_techman.pdf
Semi-Lagrangian, non-interpolating in vertical. Eulerian continuity at present.
Semi-Lagrangian with monotone option and mass correction.
non-uniform horizontal grid under test.
For details check references