A new adiabatic kernel for the MC2 model

Abstract Traditional semi‐implicit formulations of nonhydrostatic compressible models may not be stable in the presence of steep terrain when pressure gradient terms are split and lagged in time. If all pressure gradient terms and the divergence are treated implicitly, the resulting wave equation for the pressure contains off‐diagonal cross‐derivative terms leading to a highly nonsymmetric linear system of equations. In this paper we present a more implicit formulation of the Mesoscale Compressible Community (MC2) model employing a Generalized Minimal Residual (GMRES) Krylov iterative solver and a more efficient semi‐Lagrangian advection scheme. Open boundaries now permit exact upwind interpolation and the ability to reproduce simulations to machine precision is illustrated for one‐way nesting at equivalent resolution. Numerical simulations of hydrostatic and nonhydrostatic mountain waves demonstrate the stability and accuracy of the new adiabatic kernel. The computational efficiency of the model is repor...

[1]  Richard C. J. Somerville,et al.  On the use of a coordinate transformation for the solution of the Navier-Stokes equations , 1975 .

[2]  Stephen J. Thomas,et al.  The Cost-Effectiveness of Semi-Lagrangian Advection , 1996 .

[3]  M. Cullen A test of a semi‐implicit integration technique for a fully compressible non‐hydrostatic model , 1990 .

[4]  Monique Tanguay,et al.  A Semi-implicit Send-Lagrangian Fully Compressible Regional Forecast Model , 1990 .

[5]  T. Clark A small-scale dynamic model using a terrain-following coordinate transformation , 1977 .

[6]  Evelyne Richard,et al.  Simple Tests of a Semi-Implicit Semi-Lagrangian Model on 2D Mountain Wave Problems , 1995 .

[7]  H. H. Rachford,et al.  The Numerical Solution of Parabolic and Elliptic Differential Equations , 1955 .

[8]  J. Klemp,et al.  The Simulation of Three-Dimensional Convective Storm Dynamics , 1978 .

[9]  Len G. Margolin,et al.  On Forward-in-Time Differencing for Fluids: Stopping Criteria for Iterative Solutions of Anelastic Pressure Equations , 1997 .

[10]  Howard C. Elman,et al.  ITERATIVE METHODS FOR NON-SELF-ADJOINT ELLIPTIC PROBLEMS , 1984 .

[11]  S. Eisenstat,et al.  Variational Iterative Methods for Nonsymmetric Systems of Linear Equations , 1983 .

[12]  NUMERICAL SIMULATION OF SHALLOW WATER WAVE PROPAGATION USING A BOUNDARY ELEMENT WAVE EQUATION MODEL , 1997 .

[13]  H. Davies,et al.  A lateral boundary formulation for multi-level prediction models. [numerical weather forecasting , 1976 .

[14]  H. Ritchie,et al.  A Comparison of Spatially Averaged Eulerian and Semi-Lagrangian Treatments of Mountains , 1996 .

[15]  René Laprise,et al.  The Formulation of the Andr Robert MC (Mesoscale Compressible Community) Model , 1997 .

[16]  Y. Saad,et al.  GMRES: a generalized minimal residual algorithm for solving nonsymmetric linear systems , 1986 .

[17]  A. Robert Bubble Convection Experiments with a Semi-implicit Formulation of the Euler Equations , 1993 .

[18]  M. Tapp,et al.  A non‐hydrostatic mesoscale model , 1976 .

[19]  Harold Ritchie,et al.  Advantages of Spatial Averaging in Semi-implicit Semi-Lagrangian Schemes , 1992 .

[20]  Piotr K. Smolarkiewicz,et al.  Preconditioned Conjugate-Residual Solvers for Helmholtz Equations in Nonhydrostatic Models , 1997 .

[21]  André Robert,et al.  A stable numerical integration scheme for the primitive meteorological equations , 1981 .

[22]  René Laprise,et al.  Sensitivity of Internal Gravity Waves Solutions to the Time Step of a Semi-Implicit Semi-Lagrangian Nonhydrostatic Model , 1996 .

[23]  Richard Asselin,et al.  Frequency Filter for Time Integrations , 1972 .

[24]  A. Simmons,et al.  Implementation of the Semi-Lagrangian Method in a High-Resolution Version of the ECMWF Forecast Model , 1995 .

[25]  M. Desgagné,et al.  The Canadian MC2: A Semi-Lagrangian, Semi-Implicit Wideband Atmospheric Model Suited for Finescale Process Studies and Simulation , 1997 .

[26]  Andrei V. Malevsky,et al.  Spline-Characteristic Method for Simulation of Convective Turbulence , 1996 .

[27]  H. Elman Iterative methods for large, sparse, nonsymmetric systems of linear equations , 1982 .

[28]  Motohki Ikawa,et al.  Comparison of Some Schemes for Nonhydrostatic Models with Orography , 1988 .

[29]  Yousef Saad,et al.  A Flexible Inner-Outer Preconditioned GMRES Algorithm , 1993, SIAM J. Sci. Comput..

[30]  B. Golding An efficient non-hydrostatic forecast model , 1992 .

[31]  Stephen J. Thomas,et al.  Massively Parallel Implementation of the Mesoscale Compressible Community Model , 1997, Parallel Comput..

[32]  J. Crank,et al.  The numerical solution of elliptic and parabolic partial differential equations with boundary singularities , 1978 .

[33]  Len G. Margolin,et al.  On Forward-in-Time Differencing for Fluids: an Eulerian/Semi-Lagrangian Non-Hydrostatic Model for Stratified Flows , 1997 .

[34]  R. Treadon,et al.  A Tutorial on Lateral Boundary Conditions as a Basic and Potentially Serious Limitation to Regional Numerical Weather Prediction , 1997 .

[35]  Stephen J. Thomas,et al.  Parallel algorithms for semi-lagrangian advection , 1997, International Journal for Numerical Methods in Fluids.

[36]  D. Durran,et al.  A Compressible Model for the Simulation of Moist Mountain Waves , 1983 .

[37]  J. Oliger,et al.  Theoretical and practical aspects of some initial-boundary value problems in fluid dynamics , 1976 .