Conjugate gradients versus multigrid solvers for diffusion-based correlation models in data assimilation

Autor: J. Tshimanga, Philippe L. Toint, Serge Gratton
Rok vydání: 2013
Předmět:
Zdroj: Quarterly Journal of the Royal Meteorological Society. 139:1481-1487
ISSN: 0035-9009
DOI: 10.1002/qj.2050
Popis: This article provides a theoretical and experimental comparison between conjugate gradients and multigrid, two iterative schemes for solving linear systems, in the context of applying diffusion-based correlation models in data assimilation. In this context, a large number of such systems has to be (approximately) solved if the implicit mode is chosen for integrating the involved diffusion equation over pseudo-time, thereby making their efficient handling crucial for practical performance. It is shown that the multigrid approach has a significant advantage, especially for larger correlation lengths and/or large problem sizes.
Databáze: OpenAIRE