Release Notes for tiegcm2.0 ($SVN/tiegcm/tags/tiegcm2.0 in the hao repository)
Release date:  March, 2016

Source code and data files for version tiegcm2.0 is available at the TGCM download web page
http://www.hao.ucar.edu/modeling/tgcm/download.php:

Source Code and supporting utilities: tiegcm2.0.tar.gz
Data for 5.0-degree resolution model: tiegcm2.0_res5.0_data.tar.gz 
Data for 2.5-degree resolution model: tiegcm2.0_res2.5_data.tar.gz 

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Primary Modifications:

  2.5-degree horizontal resolution:
    The model has now been tuned to our satisfaction for community use at the 
    2.5-degree horizontal resolution (with four grid-points per scale height 
    in the vertical coordinate). User's are encouraged to run the model at the 
    2.5-degree resolution, since it provides a more realistic ionosphere than 
    the 5-degree model. All benchmark runs and source history files are available 
    at both 5-degree and 2.5-degree resolutions.

  Parallel dynamo: 
    The electro-dynamo code was parallelized with pure MPI. Transformations between the 
    geographic and geomagnetic grids in the MPI environment are accomplished with the 
    Earth System Modeling Framework (ESMF library). This resulted in a performance 
    speed-up of about 25% at the 5-degree resolution, and almost 50% at the 2.5-degree 
    resolution when using 64-processors on the NCAR supercomputer system.

  Helium: 
    Helium is now calculated as a major species at both resolutions.
    If a source history without helium is used (i.e., versions earlier than v2.0), 
    helium will be initialized to a global value (0.1154e-5), and will evolve from there. 
    Helium is always saved on primary histories, and can be saved on secondary histories
    as 'HE'. Thanks to Eric Sutton for leading this effort.

  Argon: 
    Argon is now calculated as a minor species. Argon is always saved on primary 
    histories, and can be saved on secondary histories as 'AR'.

  Additional diagnostics: 
    Several new diagnostic fields have been added, including N2, ZGMID, CUSP, 
    DRIZZLE, ALFA, NFLUX, and EFLUX (see src/diags.F, or the User Guide for 
    more information).

Make/Build System:

  Compilers: 
    We now support three compilers for Linux desktop systems:
    Intel, PGI, and GNU gfortran. On the NCAR supercomputer system, only Intel
    is supported.  Intel is the default compiler on both systems, because it
    consistently out-performs the other compilers.

  ESMF Library. The parallel dynamo now requires that the ESMF library
    be linked. See the User's Guide for more information.

Performance:

  Please see doc/perf.table for summary of estimated performance timings
  including average seconds per step and wallclock minutes per simulated
  day at default processor counts on linux desktop and NCAR supercomputer
  systems. The table is also in the User Guide (see index entry "perf.table").