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

  CT 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.

**  Tue Mar 25 11:49:59 2014   Andy Jacobson <andy.jacobson@noaa.gov> **

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

  Note that CT2013 uses two different atmospheric transport estimates
  within the TM5 model. Winds from the ECMWF operational forecast
  model (generally denoted with the "od" suffix) are available on a
  25-layer vertical grid from 01-Jan-2000 to 31-Dec-2005, and a
  34-layer vertical grid from 01-Jan-2006 onwards.  Winds from the
  ERA-interim reanalysis (generally denoted with an "ei" suffix) are
  available on a 25-layer vertical grid for the entire duration of the
  simulation.

  The "final across-model CT2013" CO2 fields are presented on the od
  model grid.  Even when the vertical resolution for the two models is
  indentical, the levels can be at different GPH and/or pressures.
  Thus, "ei" results are interpolated to the "od" model locations.
  This becomes more significant after 2006, when "od" results are
  available at 34 levels and the "ei" results are upscaled from 25
  levels.

  Contents of these directories:

  co2_total/

     Variable "co2": Final across-model CT2013 carbon dioxide mole fractions
     Variable "gph": "od" layer interface geopotential height
     Variable "press": "od" layer interface pressure
     Variable "temp": "od" layer temperature

  co2_components/

     Variable "bg": Final across-model CT2013 initial condition total
                    co2 at 01-Jan-2000, as advected and diffused to
                    later model time.

     Variable "bio": Final across-model CT2013 component of total co2
                     due to terrestrial biosphere exchange with
                     atmosphere since 01-Jan-2000, excluding
                     wildfires.

     Variable "fires": Final across-model CT2013 component of total
                       co2 due to wildfire emissions since
                       01-Jan-2000.


     Variable "ff": Final across-model CT2013 component of total co2
                     due to fossil fuel emissions since 01-Jan-2000.

     Variable "ocean": Final across-model CT2013 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.

  CT2013_od/co2_total
  CT2013_od/co2_components
  CT2013_ei/co2_total
  CT2013_ei/co2_components

     CO2 and meteorological fields specific to each of the transport
     models: ECMWF forecast (_od) and ERA-interim (_ei).

  
**  Wed May 14 07:13:44 2014   Andy Jacobson <andy.jacobson@noaa.gov> **

    THere is not enough room for CT2013_od and CT2013_ei on the aftp
    server.  They have been moved off that machine, but are available
    upon request to carbontracker.team@noaa.gov.