Implementation of the LANS-alpha turbulence model in a primitive equation ocean model

Physics – Atmospheric and Oceanic Physics

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Submitted to J. Computational Physics March 21, 2007

Scientific paper

10.1016/j.jcp.2008.02.018

This paper presents the first numerical implementation and tests of the Lagrangian-averaged Navier-Stokes-alpha (LANS-alpha) turbulence model in a primitive equation ocean model. The ocean model in which we work is the Los Alamos Parallel Ocean Program (POP); we refer to POP and our implementation of LANS-alpha as POP-alpha. Two versions of POP-alpha are presented: the full POP-alpha algorithm is derived from the LANS-alpha primitive equations, but requires a nested iteration that makes it too slow for practical simulations; a reduced POP-alpha algorithm is proposed, which lacks the nested iteration and is two to three times faster than the full algorithm. The reduced algorithm does not follow from a formal derivation of the LANS-alpha model equations. Despite this, simulations of the reduced algorithm are nearly identical to the full algorithm, as judged by globally averaged temperature and kinetic energy, and snapshots of temperature and velocity fields. Both POP-alpha algorithms can run stably with longer timesteps than standard POP. Comparison of implementations of full and reduced POP-alpha algorithms are made within an idealized test problem that captures some aspects of the Antarctic Circumpolar Current, a problem in which baroclinic instability is prominent. Both POP-alpha algorithms produce statistics that resemble higher-resolution simulations of standard POP. A linear stability analysis shows that both the full and reduced POP-alpha algorithms benefit from the way the LANS-alpha equations take into account the effects of the small scales on the large. Both algorithms (1) are stable; (2) make the Rossby Radius effectively larger; and (3) slow down Rossby and gravity waves.

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Implementation of the LANS-alpha turbulence model in a primitive equation ocean model does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Implementation of the LANS-alpha turbulence model in a primitive equation ocean model, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Implementation of the LANS-alpha turbulence model in a primitive equation ocean model will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-382852

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.