Even Newer Dynamics for General atmospheric modelling of the environment (ENDGame)
ENDGame is the current operational dynamical core for the Unified Model and is based on a semi-implicit semi-Lagrangian discretization of the governing equations.
ENDGame is a finite-difference model discretized on a latitude-longitude grid and is based on the fully compressible, nonhydrostatic Euler equations. However, an important aspect of ENDGame is that it is designed around an iterative approach to solving the semi-implicit aspects of the scheme. This permits more accurate coupling of the scheme to the physics parametrizations. It also produces a simpler form of the Helmholtz problem that arises from the semi-implicit discretization.
Building on recent research into the dispersion properties of Rossby waves on C-grids, ENDGame has improved handling of these meteorologically significant waves whilst retaining the same optimal properties. This has required a modification to the staggering of variables with respect to the poles. The two aspects, the different Helmholtz problem and the changes to the polar discretization, have improved the scaling of the model on massively parallel computer architectures.
ENDGame has been designed to allow the code to be switchable between various options: a nonhydrostatic and a hydrostatic formulation, deep-atmosphere and shallow-atmosphere formulations, and use of spheroidal, spherical or Cartesian co-ordinates (as appropriate).
The same model is used for NWP and Climate, in both global and LAM configurations. The LAMs, therefore, use lateral boundary conditions generated from a model using the same science.