MMM Seminar - Semi-implicit finite-volume integrators for all-scale atmospheric dynamics

MMM Seminar - Thursday, October 17, 2019 - 3:30pm

Speaker: Piotr Smolarkiewicz

Affiliation: Mesoscale and Microscale Meteorology Laboratory, NCAR

This talk outlines a novel numerical approach for accurate and computationally efficient integrations of PDEs governing all-scale atmospheric dynamics. Such PDEs are not easy to handle, due to a huge disparity of spatial and temporal scales as well as a wide range of propagation speeds of natural phenomena captured by the equations.  The novel Finite-Volume Module of the Integrated Forecasting System (IFS) at ECMWF (IFS-FVM) solves perturbation forms of the fully compressible Euler/Navier-Stokes equations under gravity and rotation using non-oscillatory forward-in-time semi-implicit time stepping and finite-volume spatial discretisation. The IFS-FVM complements the established semi-implicit semi-Lagrangian pseudo-spectral IFS (IFS-ST) with the all-scale deep-atmosphere formulation cast in a generalised height-based vertical coordinate, fully conservative and monotone advection, flexible horizontal meshing and a predominantly local communication footprint. Yet, both dynamical cores can share the same quasi-uniform horizontal grid with co-located arrangement of variables, geospherical longitude-latitude coordinates and physics parametrisations, thus facilitating their synergetic relation. The focus of the talk is on the mathematical/numerical formulation of the IFS-FVM with the emphasis on the design of semi-implicit integrators and the associated elliptic Helmholtz problem. Relevant benchmark results and comparisons with corresponding IFS-ST results attest that IFS-FVM offers highly competitive solution quality and computational performance.

Refreshments: 3:15 PM

This seminar will be webcast live at:                                                                                      

Room Number: 
FL2-1022 - Large Auditorium

Type of event:

Announcement Timing: 
Wednesday, October 9, 2019 to Thursday, October 17, 2019
Calendar Timing: 
Thursday, October 17, 2019 - 3:30pm

Posted by Nancy Kerner at ext. 8946,

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