Exercise I

Objectives

T-UGOm embedded spectral solver is a very cheap way to compute tidal solutions on a region of interest. It can easily be used by the finite difference (i.e. structured grid) community by generating a unstructured grid by cutting FD cells into 2 FE elements (triangles). A similar strategy is used to run WW3 on stretched structured grid.

Exercise I aims to run the COMODO-TOOLS softwares (symtools and symmic) that will do the grid conversion.

Starting from a ROMS NetCDF grid

You can now change directory to  :

cd ~/tuesday/Tonkin/tonkin_ex1/roms

where you will find the roms_grd.nc NetCDF grid file. Then execute:

symmic -g roms_grd.nc roms_grd.nc -source roms

On output, unstructured grid file (*.nei format) : symmic-regular.nei

Starting from a SYMPHONIE notebook (grid)

You can now change directory to  :

cd ~/tuesday/Tonkin/tonkin_ex1/symphonie

where you will find the notebook-grid (SYMPHONIE grid construction parameters) and tonkin.plg files (polygons ASCCI file to generate the land/sea mask).

First step: create SYMPHONIE NetCDF grid file

symtools -zmin 5. -b $DATA/topography/gebco/gridone.grd -n notebook-grid -p tonkin

Second step: create T-UGOm grid file (*.nei format)

symmic -g symphonie.chk.spherical.nc symphonie.chk.spherical.nc

On output, unstructured grid file (*.nei format) : symmic-regular.nei

Looking closer to the resulting unstructured grids

Let's use xscan to display the grids. First edit the startup file and fix defaults paths:

gedit ~/tuesday/Tonkin/data/tonkin.startup

Now let's play with it:

xscan -s ~/tuesday/Tonkin/data/tonkin.startup

Go to "Elements edition" menu, then use "open" in File menu to select and load the symmic-regular.nei.