Physics Modules

The parallel model adopts the use of columnar physics modules that are ``plug compatible''. The CHAMMP development group adopts the guidelines set forth in ``Rules for Interchange of Physical Parameterizations'', by Kalnay, Kanamitsu, Pfaendtner, Sela, Suarez, Stackpole, Tuccillo, Umscheid and Williamson. These rules are duplicated for reference purposes.

• A package shall refer only to its own subprograms and the ANSI FORTRAN intrinsic functions.
• A package shall provide separate set-up and running procedures, each with a single entry point. All initialization of static data must be done in the set-up procedure, and the running procedure shall not modify the static data.
• All communication with the package shall be through the argument list at the entry points.
• The package shall not use blank COMMON
• Arguments shall be clearly documented. In particular, data items shall be defined in physical terms, and identified as being: (1) needed on input and not changed, (2) needed on input and modified, (3) simply output, or (4) workspace; and EXTERNAL subprograms shall be described in detail. All data shall be in SI units.
• The horizontal index shall be the innermost of FORTRAN arrays. The range of this index processed on each call shall be specifiable through the argument list.
• The number of levels the package uses shall be specifiable through the argument list.
• All dimensions of dummy argument arrays shall appear in the argument list.
• No array index shall exceed its declared dimension.
• The package shall not use the STOP statement.
• I/O form the package shall be limited to diagnostic output written to FORTRAN units specified in the argument list.

As point physics methods are developed these should also be plug-compatible with the appropriate extension and modification of the above rules.