Overview

In addition to hgrid.ll (lon/lat), some pre-processing scripts need the horizontal grid on a projected coordinate system. The hgrid.cpp described here is based on CPP projection (see a description of the coordinate system here).

Scripts

A Fortran script is provide in Git to perform the projection from lon/lat to CPP:

[schism_git_dir]/src/Utility/Pre-Processing/NWM/Grid_manipulation/cpp.f90

, which requires the user input of the origin of the system in lon/lat.

This is also provided in:

[schism_git_dir]/src/Utility/Pre-Processing/NWM/Grid_manipulation/cpp.in

To generate hgrid.cpp from an existing hgrid.ll, you can do the following on the command line:

cp -rL [schism_git_dir]/Grid_manipulation/ [your_run_dir]
cd [your_run_dir]/Grid_manipulation
./auto.pl

The perl automation runs the fortran script as “./cpp < cpp.in” and do some housekeeping. Ignore the warning messages on hgrid.utm.*, which is not used for the 2D setup.

The “Grid_manipulation” folder also contains small utilities that reproduce some frequently used functions of the Acetool.