**  Fri May 11 09:17:10 2012   Andy Jacobson <andy.jacobson@noaa.gov> **

  CT2011 co2 molefractions files are now netCDF version 4, using
  internal compression.  This has shrunk the file size by a factor of
  about 3, which is important for efficient transmission of the data.
  However, users may find that they need to update their software to
  handle netCDF-4 files.

  IDL - supported as of version 8.0
  Matlab - as of R2010b
  R - using add-on "ncdf4"
  python - using add-on "netcdf4-python"

  Q: Where can I learn more about netCDF4, and download the netCDF4
  software? 

  A: Unidata maintains an extensive website at
  http://www.unidata.ucar.edu/software/netcdf/ where you can learn
  about netCDF4 and get the open-source netCDF4 software.

**  Fri May 11 09:25:54 2012   Andy Jacobson <andy.jacobson@noaa.gov> **


  Note that variables are provided separately for each of our two
  transport model domains (global 3x2 and North America 1x1)

  Note that CT2011 uses a 25-layer model from 01-Jan-2000 to
  31-Dec-2005, and a 34-layer model from 01-Jan-2006 onwards.


  Contents of these directories:

  co2_total/

     Variable "co2": Final CT2011 carbon dioxide mole fractions
     Variable "gph": layer interface geopotential height
     Variable "press": layer interface pressure
     Variable "temp": layer temperature

  co2_components/

     Variable "bg": initial condition total co2 at 01-Jan-2000, 
                    as advected and diffused to later model time.

     Variable "bio": component of total co2 due to terrestrial
                     biosphere exchange with atmosphere since
                     01-Jan-2000, excluding wildfires.

     Variable "fires": component of total co2 due to wildfire
                       emissions since 01-Jan-2000.


     Variable "ff":  component of total co2 due to fossil fuel
                     emissions since 01-Jan-2000.

     Variable "ocean": component of total co2 due to air-sea
                       exchange since 01-Jan-2000.

     co2_total = bg + bio + fires + ff + ocean

     Note that bg, ff, and fires are strictly positive, but bio
     and ocean are largely negative, since they represent sinks
     of atmospheric carbon dioxide.

  suite/

     Model-by-model estimates of CT2011 total co2.


**  Thu May 17 15:42:26 2012   Andy Jacobson <andy.jacobson@noaa.gov> **

  Original versions placed here on 11 May had scrambled timesteps.
  They have been removed and replaced with versions created by piping
  filenames through sort before feeding to ncrcat.  Fixed versions
  have history attribute with a 15/16 May 2012 creation date, as:
  
	history = "Created 2012-05-15 20:37:56 UTC by ./ct11f.ml91.x."



**  Fri May 18 10:41:24 2012   Andy Jacobson <andy.jacobson@noaa.gov> **

  Discovered that the glb3x2 fields, for the final timestep in each
  week, did not have the nam1x1 zoom regions filled with data.  For
  this single timestep in each week, the nam1x1 region would show up
  as missing data.  This oversight was corrected, and new files are
  now being synched to the ftp server.  The history attribute for the
  newest files will show a creation date of 2012-05-18.  No other
  changes were made to the data.


**  Fri Jul  6 10:56:32 2012   Andy Jacobson <andy.jacobson@noaa.gov> **

  The temperature fields did not have time variability.  Reprocessed
  to fix this oversight.  CO2 and other fields should remain unchanged. 

  Added version number to the version attribute string, now looks like:

:version = "CT2011 mole fraction output revision 3 of Mon Jul  2 12:55:42 2012" ;

  This revision of the output is given number 3.