Mission Statement:

Design and implement a dycore interface.

Goals:

. Make it easier for scientists to experiment with new dycores in CAM.

. Make it easier to maintain the three dycores currently supported in CAM. 

. Move code towards being able to evaluate an ESMF implementation of separate
  dynamics and physics components.

Motivation:

The current code supports three dycores by maintaining separate copies of
the high level driver and initialization routines (e.g., stepon, inital and
inidat).  This is because the dycore specific internals are present in this
high level driver code.  By designing dycore independent interfaces the
difference between the dycores can be encapsulated at a lower level and the
high level code does not need to be replicated for each dycore.

Authority: 
   AMWG

Project Lead:
   Eaton

Scientific Lead: 
   None

Current Status:

The initial design is in http://www.cgd.ucar.edu/cms/eaton/cam/atm_desdoc

In the context of his ESMF work Erik has created a version of the dynamics
state and tendency derived types, and created a dynamics run method.  Using
this dycore interface he then created a single version of stepon and inital.

In concurrent work by John Drake and Mike Ham on 2D decomposition versions
of the spectral dycores dynamics state and tendency types were also
defined, but differently from Erik's version.

Will Sawyer has implemented the FV dycore as an ESMF gridded component.
That design makes use of import and export states which is also different
from the dynamics state and tendency types of the initial design.

Implementation Plan:

o) Discuss pros and cons of the different designs decide how to move
   forward.  Need to coordinate with the ORNL and NASA.  (By end of
   April 2005)

o) Start to modify the work on dycore interfaces from Erik's
   subroutinization branch to implement design changes in the spectral
   dycores.  (September 2005)

o) Contributions to FV dycore from Will Sawyer?


Resources:

   Kluzek    10 months  (Erik probably won't have any more time to devote
                         to dycore issues.)
   Eaton      2 months
   ORNL (Drake, Ham, Worley) ??
   NASA (Sawyer, Putman) ??