7 Glossary

component

A component is the software instatiation of a climate system model component such as the atmsophere, ocean, sea ice, or land surface.

package

A package is an independently testable coding unit. The package concept corresponds closely with a class. Packages are composed of modules.

module

Modules correspond to Fortran 90 modules. Modules are composed of data objects and procedures that act on these objects.

derived data type

A derived data type is a user defined definition of logical construct to be used as an abstraction in the software. Derived types are supported in Fortran 90.

package interface

A package interface is the specification of use for a package. It includes the procedures for initializing and calling the package as well as the description for the log, history and restart mechanisms within the package.

column

A column is an single atmospheric columns corresponding to a lat-lon point. The column physics works on atmospheric columns.

chunk

A chunk is an arbitrary collection of atmospheric columns. The chunk is used as the fundamental processing unit in the physics package.

block

A block is a contiguous set of points of a 3 dimensional grid. The block is the fundamental processing unit in the dynamics package. A block typically has halo (or ghost) extensions.

patch

A patch is a special case of a block with full vertical extent but only partial lat and lon extent.

slab

A slab is a special case of a block with full longitudinal and vertical extent but only partial latitudinal extent.

slice

A slice is a slab with full longitudinal and vertical extent but only one latitude.

library layer

The library layer comprises the software that is machine (or installation) dependent. This is the lowest level of a three tiered software architecture, the other two layers are the utility layer and the model layer.

utility layer

The utility layer comprises the software that is independent of model and machines. This is the middle level of a three tiered software architecture, the other two layers are the model layer and library layer.

history file

A history file is output that records atmospheric variables for a particular time period.

restart file

A restart file is output that records atmospheric model's state at a particular time for use in restarting the model from that point.