Particle tracking, and differences between AGRIF and Rutgers

[jpringle]

Colleagues --

I am trying to do some particle tracking in ROMS output; the model runs were not done by me, and were made with ROMS-AGRIF V3. I have several questions here; I am also asking them on the AGRIF forum.

1) Has anyone used LTRANS v2 with AGRIF?
2) Is the vertical stretching and transform in AGRIF the same as VTRANSFORM=VSTRETCHING=1 in the Rutgers code?
3) in AGRIF, the w-output has a vertical dimension of s_rho instead of s_w; what have they done? Is the missing level the one closest to the bottom? (This is annoying -- while omega=0 at the bottom, w in general will not at the bottom unless it is flat).
4) Has anyone used ARIANE with AGRIF output? Or some other AGRIF oriented particle tracking code?

I know this is not quite the right forum for this, but I wish to take advantage of someone else's work on this. Hope springs eternal...

Thanks,
Jamie Pringle
University of New Hampshire

[kate]

I can't answer the AGRIF questions, but I can say that some of us are working to make tracmass work more seamlessly with ROMS output. Tracmass was designed to work with many different ocean models, so it has parts that are different for the different models it's been used with and any AGRIF differences can be accommodated. My version of this thing is on github

You might enjoy that it has Python tools: pytraj and friends (njord and projmap).

[jpringle]

As always, thanks Kate!

I will look at tracmass and see how easy it is to incorporate behavior and vertical mixing.

LTRANS will require some recoding to recreate w or omega from u and v

ARIANE has a series of weird coordinates to specify time and inititial condition that hurt my brain. If anyone needs code to make these initial conditions from a roms grid, they can ask me. It has solid numerics that respect the continuity equation. Behavior and mixing are a pain in this tracking code.

The nice thing about standards is there are so many of them.

Jamie