This file documents updates to the v4.2 data structure and release.

No data will be changed, but it may be added to.  Typically this will be in
an errata subdirectory.  In the event of a major issue, a new release would
be made with a different version number.


   Date      |    Notes
----------------------------------------------------------------------------
27 May 2019  | Initial release of:
             |   Product User Guide (v4.0)
             |   daily netCDFs  (sinusoidal and geographic projection, all products and subsets)
             |   5-day composite netCDFs (sine proj; all products and subsets)
             |   8-day composite netCDFs (sine proj; all products and subsets)
             |   monthly composite netCDFs (sine proj; all products and subsets)
             |   PNG visualisations of the above (rendered in geo projection only)
             |
7 Feb 2020   | Update of:
             |   Product User Guide (v4.2)
             |   All netcdf and png files updated; errors in calculating chlorophyll and Kd
             |   have been fixed. In both cases, chlorophyll and Kd, error was in 
             |   implementation of chunking algorithm, plus Kd algorithm had an additional
             |   issue: the value of bbw was too high (it was bw not bbw)