[MITgcm-support] OS7MP vs SOM

[Christopher L. Wolfe]

Hi modelers,

I'm currently using the 3rd order direct space-time advection scheme  
with a flux limiter (scheme 33) in a series of eddy-resolving  
simulations. However, I'm finding that the advection scheme is doing  
a lot of mixing (as much or more than the background Laplacian  
diffusivity), so I'm shopping around for a less diffusive advection  
scheme. The "News" section of the web site mentions that two new low- 
diffusivity schemes have recently been implemented: the one-step 7th  
order monotonicity preserving scheme (OS7MP) and Prather's second  
order moments scheme (SOM). Does anyone have any experience with  
these two schemes? I'm especially interested in the performance trade- 
offs involved in two schemes. I know that OS7MP requires a 4 point  
halo, which could have a large performance impact in my case, since  
my tiles are rather small. As near as I can tell, SOM requires  
nothing more than the standard 3 point halo, but perhaps other  
performance costs creep in elsewhere?

Any advice, testimonials, or warnings would be helpful.
Thanks,
Christopher

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Dr. Christopher L. Wolfe                   858-534-4560
Physical Oceanography Research Division    OAR 357
Scripps Institution of Oceanography, UCSD  clwolfe at ucsd.edu
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