ICS is a fundamental parameter in the fort.15 file that defines the coordinate system and the desired projection. The value of ICS also has an important consequence for the choice of the Coriolis CORI parameter of the fort.15 file.
Available ICS Values
ICS Value

Shortname

Description

1

Cartesian

Points in the fort.14 are already mapped onto an arbitrary Cartesian coordinate system, e.g., UTM. Also useful for idealized problems.

2

Geographic, CPP, no curvature

Points in the fort.14 are specified in geographic coordinates, which will be projected using the CPP (equidistant) cylindrical mapping by ADCIRC. The curvature of the Earth is not accounted for.

20

Geographic, Equalarea

Points in the fort.14 are specified in geographic coordinates, which will be projected using the Equalarea cylindrical mapping by ADCIRC. The curvature of the Earth is correctly accounted for.

21

Geographic, CPP

Points in the fort.14 are specified in geographic coordinates, which will be projected using the CPP (equidistant) cylindrical mapping by ADCIRC. The curvature of the Earth is correctly accounted for.

22

Geographic, Mercator

Points in the fort.14 are specified in geographic coordinates, which will be projected using the Mercator (conformal) cylindrical mapping by ADCIRC. The curvature of the Earth is correctly accounted for.

23

Geographic, Miller

Points in the fort.14 are specified in geographic coordinates, which will be projected using the Miller cylindrical mapping by ADCIRC. The curvature of the Earth is correctly accounted for.

24

Geographic, GallStereographic

Points in the fort.14 are specified in geographic coordinates, which will be projected using the GallStereographic cylindrical mapping by ADCIRC. The curvature of the Earth is correctly accounted for.

 The values 2024 can also be set to a negative value to implement an arbitrary rotation of the geographic coordinates by ADCIRC. This is primarily used to ensure that Earth's poles are rotated onto land to eliminate the singularity in the Spherical coordinate form of the governing equations. ADCIRC's outputs will be displayed on the original unrotated coordinate system.