FN Archimer Export Format
PT J
TI A Fast Monotone Discretization of the Rotating Shallow Water Equations
BT 
AF Roullet, Guillaume
   Gaillard, Tugdual
AS 1:1;2:1;
FF 1:;2:;
C1 Univ. Brest, CNRS, IRD, Ifremer, Laboratoire d'Oc\'eanographie Physique et Spatiale (LOPS), IUEM, Brest, France
C2 UBO, FRANCE
UM LOPS
IN WOS Cotutelle UMR
   DOAJ
IF 6.8
TC 1
UR https://archimer.ifremer.fr/doc/00700/81226/85518.pdf
   https://archimer.ifremer.fr/doc/00700/81226/91818.pdf
LA English
DT Article
DE ;RSW model;WENO;implicit numerical dissipation;speed;Python
AB This paper presents a new discretization of the rotating shallow water equations and a set of decisions, ranging from a simplification of the continuous equations down to the implementation level, yielding a code that is fast and accurate. Accuracy is reached by using WENO reconstructions on the mass flux and on the nonlinear Coriolis term. The results show that the build-in mixing and dissipation, provided by the discretization, allow a very good material conservation of potential vorticity and a minimal energy dissipation. Numerical experiments are presented to assess the accuracy, which include a resolution convergence, a sensitivity on the the free-slip vs. no-slip boundary conditions, a study on the separation of waves from vortical motions. Speed is achieved by a series of choices rather than a single recipe. The main choice is to discretize the covariant form written in index coordinates. This form, rooted in the discrete differential geometry, removes most of the grid scale terms from the equations, and keep them only where they should be. The model objects appearing in resulting continuous equations have a natural correspondence with the grid cell features. The other choices are guided by the maximization of the arithmetic intensity. Finally this paper also proves that a pure Python implementation is not only possible but also very fast, thanks to the possibility of having compiled Python. As a result, the code performs 2 TFlop per second using thousand cores. 
PY 2022
PD FEB
SO Journal Of Advances In Modeling Earth Systems
SN 1942-2466
PU Wiley
VL 14
IS 2
UT 000763472100017
DI 10.1029/2021MS002663
ID 81226
ER

EF