A performance study of horizontally explicit vertically implicit (HEVI) time-integrators for non-hydrostatic atmospheric models

Autor(es)

Giraldo, Francis X. ; Alves, Felipe A. V. de Braganca ; Kelly, James F. ; Kang, Soonpil ; Reinecke, P. Alex

• Tipo de documento: Artigo Científico
• Fonte: Journal of Computational Physics; v. 515, p. 22-pg., 2024-07-18.

Resumo

We conduct a thorough study of different forms of horizontally explicit and vertically implicit (HEVI) time-integration strategies for the compressible Euler equations on spherical domains typical of nonhydrostatic global atmospheric applications. We compare the computational time and complexity of two nonlinear variants (NHEVI-GMRES and NHEVI-LU) and a linear variant (LHEVI). We report on the performance of these three variants for a number of additive RungeKutta methods ranging in order of accuracy from second through fifth, and confirm the expected order of accuracy of the HEVI methods for each time-integrator. To gauge the maximum usable time-step of each HEVI method, we run simulations of a nonhydrostatic baroclinic instability for 100 days and then use this time-step to compare the time-to-solution of each method. The results show that NHEVI-LU is 3x faster than NHEVI-GMRES, and LHEVI is 8x faster than NHEVI-GMRES, for the idealized cases tested. The baroclinic instability and inertia-gravity wave simulations indicate that the optimal choice of HEVI method is LHEVI. For the fastest time-to-solution, the second and third order methods are best although the better accuracy of the high-order methods (particularly the fourth order method) should be considered. In the future, we will report on whether these results hold for more complex problems using, e.g., real atmospheric data and/or a higher model top typical of space weather applications. (AU)

• Processo FAPESP: 23/00447-7 - Dinâmica Numérica em malhas esféricas de Voronoi para simulações com resolução de malha na "gray zone" de turbulência
• Beneficiário: Felipe Augusto Ventura de Bragança Alves
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado