Hi ROMS experts,
USGS has put together a very nice tutorial for 2-level grid refinement/nesting in ROMS in its COAWST_User_Manual. But I am not so sure about how to determine the values of 'Lm' and 'Mm' for more refined grids (Lm and Mm are Number of I/J-direction INTERIOR RHO-points in the 'ocean*.in').
Say I have a parent grid with the size of h as [Mp1, Lp1].
The child grid has a h of [Mp2, Lp2], and a refinement ratio of 5:1.
I also have grandchild grid of [Mp3, Lp3] and a refinement ratio of 3:1.
I also have a great grandchild grid of [Mp4, Lp4] and a refinement ratio of 7:1.
For 'Lm' and 'Mm' , I already know that
Lm1=Lp1-2, and Mm1=Mp1-2;
Lm2=Lp2-7, and Mm2=Mp2-7;
What about
Lm3=?, and Mm3=?
Lm4=?, and Mm4=?
What's the general rule?
My guess is that
Lm3=Lp3-2-5-3=Lp3-10, Mm3=Mp3-10;
Lm4=Lp4-2-5-3-7=Lp4-17, Mm4=Mp4-17;
But I am not very confident of my guessing.
Can someone please help?
Btw, What are the things that I should look out for when I do grid refinement of multiple levels (>3)? Your sharing of your experience is truly appreciated.
Thanks a lot.
Mike Y.