July 15, 2007
-------------

Version 1 of the Level 2 files for the Niwot Ridge, Colorado site (US-NR1)
were posted and cover the period 1998 to 2003.


September 26, 2007
------------------

The corresponding initial version of the Level 3 and 4 files for US-NR1
were posted.


March 4, 2008
-------------

Version 2 of the L2 files for US-NR1 were posted with data through 2005.


April 21, 2008
--------------

After review of the Version 1 L3 and L4 files previously available for
Niwot Ridge by the Russ Monson team, it was realized the L2 FC values
were already storage corrected and thus adjusted again during creation
of the L3 and L4 data products. New data are being processed and new L2,
L3, and L4 data products for Niwot Ridge will be available soon.


July 17, 2008
-------------

New L2 files (Version 3) were posted with the corrections stated above
and slight modifications to the header regarding the AmeriFlux fair-use
data policy.  These V3 L2 files cover the period 1998-2007.


October 12, 2008
----------------

The corresponding L3 and L4 files derived from the V3 L2 files were
posted.


July 22, 2010
-------------

New L2 files (Version 4) were posted and contain data from 1998 to 2008.
All variables and units are reported in the AmeriFlux network-wide
conventions.


October 11, 2011
----------------

New L2 files (Version 5) were posted for the Niwot Ridge site (US-NR1)
and provide data from 1998 to 2010.  This new version contains sensible
heat, latent heat, and CO2 fluxes which were reprocessed/corrected for
all years by Sean Burns and thus replace all values from previous versions.


April 12, 2012
--------------

New L2 files (Version 6 - V006) were posted for the Niwor Ridge site
and cover the period 1998 to 2011.  Pre-2011 data did not change from
Version 5.  Details on the CDIAC processing of the original files provided
by the Sean Burns to produce the V006 L2 files are provided at

ftp://cdiac.ornl.gov/pub/ameriflux/data/Level2/Sites_ByName/Niwot_Ridge/with_gaps/report_Niwot_Ridge.html