Running WaveWatch with multiple nests embedded

[bricheno]

Hello wave modellers,

Is there a way to configure multiple individual nests?

I can add the nests in the parent model through ww3_grid.nml like this:

&OUTBND_COUNT_NML
OUTBND_COUNT%N_LINE = 3652
/
&OUTBND_LINE_NML
OUTBND_LINE(1)=
.... etc

which writes everything out to nest1.ww3. This works fine for one embedded child model.

Next, I extend the list of OUTBND_LINE to cover 2 different domains.
but when I try to pick-up the lateral boundary data from the parent to the child, it errors like this:

*** WAVEWATCH III ERROR IN W3IOBC :
POINT3599 -0.108828E+02 -0.728750E+01 NOT LOCATED IN GRID
EXTCDE MPI_ABORT, IEXIT= 12

Is this because everything is being written to nest1.ww3?
Is there a different syntax to generate a set of several separate nests (nest1 nest2 ... etc)? Which are in different regions?

Thanks for any answers!
Lucy

Dr Lucy Bricheno | Team leader - Coastal Ocean
National Oceanography Centre, Joseph Proudman Building, 6 Brownlow Street, Liverpool, L3 5DA
+44 (0)151 795 4800 | [email protected] | @LBricheno
https://noc.ac.uk/

[ukmo-ccbunney]

Hi @bricheno ,
To output multiple nest files you need to delimit your list of output boundary points with a -1 in the "number of points" column (the last column). This effectively terminates the current nest file and starts a new file (nestXXX+1) with the proceeding points.

It's detailed in the WW3_GRID example file in inp/ww3_grid.inp. Here's an excerpt:

WW3/model/inp/ww3_grid.inp

Lines 855 to 866 in e085bcf

	$ Output boundary points --------------------------------------------- $
	$ Output boundary points are defined as a number of straight lines,
	$ defined by its starting point (X0,Y0), increments (DX,DY) and number
	$ of points. A negative number of points starts a new output file.
	$ Note that this data is only generated if requested by the actual
	$ program. Example again for spherical grid in degrees. Note, these do
	$ not need to be defined for data transfer between grids in the multi
	$ grid driver.
	$
	1.75 1.50 0.25 -0.10 3
	2.25 1.50 -0.10 0.00 -6
	0.10 0.10 0.10 0.00 -10

Chris.