Initial Results from the Integration of Earth and Space Frameworks

1
Initial Results from the Integration of Earth and
Space Frameworks
Cecelia DeLuca/NCAR, Alan Sussman/University of
Maryland, Gabor Toth/University of Michigan
Abstract There is increasing call to couple
Earth and space models, as the interplay between
the regions is an active topic of basic research
and a key factor in operational prediction
systems. Two pilot projects to combine Earth and
space software frameworks have produced initial
technical results.  The projects, which were
initiated under NASA and NSF funding, demonstrate
1) transfers of data between models using the
Earth System Modeling Framework (ESMF) and those
that are part of the Center for Integrated Space
Weather Modeling (CISM) and 2) transfers of data
between models using ESMF and those running under
the Space Weather Modeling Framework (SWMF).  We
describe technical approaches, capabilities
achieved, and possible next steps.
Framework Comparison Table
Pilot Projects
1. ESMF and CISM / InterComm Coupling
Motivation The main motivations for interfacing
ESMF-based Earth simulations to space simulations
and vice versa are the desire to better express
boundary conditions for these domains, and the
desire to improve representation of the boundary
region. End goals are to deepen understanding of
physical processes and to produce better
forecasts. The ability to exchange component
versions between the CISM and SWMF frameworks
would afford space weather researchers more
opportunities for experimentation and
collaboration. There are also a number of upper
atmosphere researchers who are interested in
implementing their component versions in an
ESMF-compatible way.

• Modifications Required
• 3 new ESMF functions required
• 1 to translate ESMF array descriptors into
  InterComm descriptors
• ESMF_ArrayExternalICTranslate()
• 2 to export/import ESMF sub-arrays to another
  program
• ESMF_ArrayExternalICSend()
• ESMF_ArrayExternalICRecv()
• Status
• Implementation of prototype complete and tested
• Currently limited to block array distributions
• InterComm functions will appear as option in ESMF
  release
• Prototype coupling of ESMF model to NCAR space
  weather model is being discussed
• Future Work
• We will demonstrate in a simple model the
  ability to execute a data transformation between
  an ESMF component and a CISM component using
  InterComm, with the ESMF component using ESMF
  interfaces and the CISM component using native
  InterComm interfaces.

ESMF App Driver
ESMF Coupler
ESMF Component 1 (e.g. land)
ESMF Component 2 (e.g. atm)
Multiple executables
FRAMEWORK Earth System Modeling Framework (ESMF)
CISM Model
Example GEOS-5 AGCM

• The ESMF architecture is based on components with
  standard interfaces and standard methods
• An ESMF application runs as a single executable
• New components can be added to the application
  systematically
• Data in and out of components are state types
  that contain fields, bundles of fields, arrays,
  or nested states
• Toolkits include regridding and redistribution
  methods and utilities such as time management
• ESMF is free for download at http//www.esmf.ucar.
  edu

InterComm data transfer and sequencing

• Configuration
• InterComm is used for data transfers between an
  ESMF application and a CISM model (or other
  non-ESMF code)
• These are in separate executables
• Data transfers can be from anywhere, to anywhere
• Minimal changes to codes
• Each code doesnt need to know anything about the
  internals of the other

FRAMEWORK Space Weather Modeling Framework (SWMF)
Solar Corona
Eruptive Event Generator
Inner Heliosphere
Solar Energetic Particles
Photosphere to Corona

• The SWMF architecture is based on components with
  generic interfaces
• A SWMF application runs as a single executable
• Many different configurations may be run
• The SWMF is freely available at
  http//csem.engin.umich.edu

Coming Soon
2. ESMF and SWMF Coupling
Global Magnetosphere
Radiation belts
Similarities Between ESMF and SWMF ESMF and
SWMF are layered and structured in a similar
fashion (see diagrams below). This made it
rather straightforward to modify the SWMF so that
it could be run as an ESMF component. Problems
that occurred during integration were due largely
to the immaturity of aspects of the ESMF software
at the time of the implementation.
ESMF SWMF
SWMF
ESMF App Driver
ESMF Coupler
Conclusions
Coming Soon
Inner Magnetosphere
Coming Soon
Plasmasphere
ESMF Earth System Component
ESMF SWMF Component
Ionosphere Electrodynamics
Upper Atmosphere
Polar Wind
The initial results from these pilot projects are
proof of concept that SWMF components, CISM
components, and ESMF components can be connected
to each other to create applications. A natural
next step is to explore the possibility of
component exchanges between the CISM and SWMF
frameworks, perhaps mediated by ESMF interfaces.
SWMF Driver
FRAMEWORK Center for Integrated Space Weather
Modeling (CISM) / InterComm
Single Executable

• In CISM applications, the InterComm library
  (University of Maryland) is used for parallel
  data transfers between models that are in
  separate executables
• The Overture framework (LLNL) for solving PDEs in
  complex moving geometries is used to write
  coupling code, which may be put in its own
  separate executable or within a subroutine of one
  of the models being coupled
• The approach requiress minimal modification to
  existing programs
• InterComm and Overture are both general purpose,
  freely downloadable packages

• Configuration
• The entire SWMF is wrapped as an ESMF component
• The SWMF component can communicate data to one or
  more Earth system components
• The application is run using an ESMF driver
• The application runs as a single executable

• Status
• Implementation of prototype complete and tested
• ESMF functions appear as options in the SWMF
  distribution