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The contents of development dcpam

The following points are considered in development of dcpam.

  • Fortran90 is introduced: suitable program language for sharing and handing down the source code
    In order to realize suitable program structure for sharing and handing down the model, Fortran 90 is introduced as a program language. In writing the source code, we will follow Japan Meteorological Agency Fortran 90 coding rule to improve the readability of source code. Thereby, sharing and handing down dcpam are expected to become easy.

  • To be applied for the planetary atmosphere (ex. Mars, Venus):
    In order to make dcpam easily apply to the Earth, Mars, and Venus atmosphere, the structural programming is required in writing the source code. The source code of dcpam is composed of three type subroutines: the application routine which calculates physical process, the common routine which does not have to be changed and modified in applying to each planet, and the lower routine which performs subcontract work of the common routine. The Fortran 90 module is useful for realizing these program structure with ease. Furthermore, the link method of each subroutine and parameter input are considered so that it is not necessary to recompile in changing of planetary parameter and exchanging physical processes. It will result in large improvement in efficiency of various parameter and sensitivity studies by use of GCM.

  • Easy generation of reduced system models:
    In understanding results of GCM simulation, it is effective to compare the result of GCM with that of reduced system model which is reduced spatial dimension or simplified particular physical process of GCM. We consider automatic generation of such a reduced system model from GCM by only changing the argument of make program, as "make 1D". The reduced system models now considerd are 1 dimensional model (radiative convective model and energy balance mode) and 2 dimensional axsymmetric model.

  • Incorprating network transparent data structure:
    In the case that the computer architecture which performs program execution and its data analysis differs from each other, it is prefer that the data structure has network transparency which can cover the difference of computer architecture. Moreover, the numerical simulation data can be circulated through the network like observation date if self-descriptiveness is given to the numerical simulation data. We try to give these characters to the date structure of dcpam by use of gtool4/netCDF conventions.

  • High portability which guarantees execution of dcpam on various type computers:
    In order to utilize a numerical model as educational resources, high portability which guarantees execution of the model on various type computers is required. The architectures considered as a platform of dcpam are Intel 80386 system (Windows and Linux) and supercomputer produced by HITACHI, Fujitsu and NEC. For the other architecture, we try to improve portability of dcpam by following Fortran 90 standard conventions as well as possible.

  • Preparing detail documents of the model:
    Many documents required for the software as educational resources are prepared: code reference which can be useful for reading and learning the source code, installation and execution guide, sample experiment collection which shows fundamental performance of the model. Thereby, the user of dcpam can study atmospheric general circulation and perform numerical experiment by himself.
Dcpam will be able to download from GFD Dennou Club www server. For academic and educational purposes, use, copy and modification of dcpam are permitted as long as you don't try to pretend that you wrote it.

GFD Dennou Club staff dcstaff@gfd-dennou.org
2004/07/20 last updated by Masatsugu Odaka