Hi, 
I am trying to run a case where I have 4 nested layers refine grid case.  I create the 3 refine grids using coarse2fine fucntion.  
I also used contact.m to create my contact file.
My grids are 1:5 refined factor from the one before.  Each grid is inside of the one before. I read that the dt needs to be decrease by the refine factor and also that it needs to be divisible of the donot grid.
I ran the case of 3 nested without problem.  DT == 30.0d0 6.0d0 1.0d0
However I am trying now to incorporated my last and final nested grid, but is blowing up and I am not sure how to solve the problem.  The first time I ran it it was blowing up because the donor grid needs to be an exact divisible number.
I change it to DT == 30.0d0 6.0d0   1.0d0  1.0d0  and now I get the following error:
 PUT_REFINE2D - unbounded contact points temporal:  interpolation:
  cr       = 03        dg         = 02        ng         = 03
  iic(dg)  = *******   told       = 1         tnew       = 2
  iic(ng)  = 0000008   Wold       =  1.83333  Wnew       = -0.83333
  time(ng) = *******   time(told) = *******   time(tnew) = *******
 PUT_REFINE2D - unbounded contact points temporal:  interpolation:
  cr       = 03        dg         = 02        ng         = 03
  iic(dg)  = *******   told       = 1         tnew       = 2
  iic(ng)  = 0000008   Wold       =  1.83333  Wnew       = -0.83333
  time(ng) = *******   time(told) = *******   time(tnew) = *******
 PUT_REFINE3D - unbounded contact points temporal:  interpolation:
  cr       = 03        dg         = 02        ng         = 03
  iic(dg)  = *******   told       = 1         tnew       = 2
  iic(ng)  = 0000008   Wold       =  1.83333  Wnew       = -0.83333
  time(ng) = *******   time(told) = *******   time(tnew) = *******
 Elapsed CPU time (seconds):
 Node   #  0 CPU:      21.731
 Node   #  0 CPU:      21.747
 Node   #  0 CPU:      21.747
 Node   #  0 CPU:      21.747
 ROMS/TOMS - Output NetCDF summary for Grid 01:
             number of time records written in HISTORY file = 00000001
 ROMS/TOMS - Output NetCDF summary for Grid 02:
             number of time records written in HISTORY file = 00000001
 ROMS/TOMS - Output NetCDF summary for Grid 03:
             number of time records written in HISTORY file = 00000001
 ROMS/TOMS - Output NetCDF summary for Grid 04:
             number of time records written in HISTORY file = 00000001
 Analytical header files used:
     ROMS/Functionals/ana_btflux.h
     ROMS/Functionals/ana_smflux.h
     ROMS/Functionals/ana_stflux.h
 ROMS/TOMS - Fatal algorithm result .. exit_flag:   8
Is this is because I have to add the DT from the first grid to be able to always be a factor of 5, is that the case then it might blow up bc the dt is too high?
I attached my contact file and my input file.
I am new trying to understand the contact file, I just want to make sure that is not the problem.
Thanks, 
Legna
			
							Four Nested Grid
- 
				TorresGarcia
 - Posts: 6
 - Joined: Wed May 09, 2012 8:41 pm
 - Location: University of South Carolina
 
Four Nested Grid
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Re: Four Nested Grid
my experience with the nesting is that the child grids do not have to step on a time scale factor equal to the spatial scale factor. That is a recommendation, but not a requirement. I have not seen that error before, but you should be able to use dt of the child as the same as the parent. You could  also try:
DT == 30.0d0 6.0d0 1.0d0 0.5d0
and see if that works.
			
			
									
									
						DT == 30.0d0 6.0d0 1.0d0 0.5d0
and see if that works.