Alternatives to the Robert-Asselin filter

作者：Marsaleix Patrick^*; Auclair Francis; Duhaut Thomas; Estournel Claude; Nguyen Cyril; Ulses Caroline

来源：Ocean Modelling, 2012, 41: 53-66.

DOI：10.1016/j.ocemod.2011.11.002

• Leap Frog
• Physical mode
• Computational mode
• Robert-Asselin filter
• Laplacian filter
• TDI filter
• TDE filter
• FD filter
• RAW filter
• Kinetic energy balance
• Oscillation equation

The Leap Frog time stepping scheme (hereafter LF) partly loses its conservation properties when a Robert-Asselin filter (hereafter RA) is used to damp the computational mode. The LF + RA scheme actually leads to a well-known long term attenuation of the physical mode. Besides, the stability of the LF, e.g. the maximum permitted time step, is lowered by the use of the RA. Several methods, derived from the Laplacian approach of Marsaleix et al. (2008), are presented as an alternative to the RA. It appears that the physical mode is eventually much less impacted by higher order time filters. However, in some cases, the stability of the time stepping scheme becomes worse than that of the LF + RA. A five points scheme finally appears to preserve both the amplitude of the physical mode and the stability of the time stepping scheme. The analysis of these filters is based on a triple approach: the kinetic energy balance, the amplification factors of the oscillation equation, numerical experiments performed with a 3D circulation ocean model.

• 出版日期2012