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Up Topic Announcements / Ocean Color Announcements / Recent degradation of the NASA Suomi-NPP SST product
- By SeanBailey Date 2019-02-19 12:14 Edited 2019-02-21 13:00
It has recently become apparent that the characteristics of the Suomi-NPP NASA
SST products (R2016.0) underwent a significant change in mid September 2018. 
At that time, the OBPG updated forward processing to use a new version (v3.0) of
the VIIRS Level-1 processing software.  This version outputs the M13 band
(4-micron) as a 32bit integer.  Previously the product was stored as a 16bit
integer.   A corresponding change was not made to the Level 2 processing code,
resulting in an erroneous treatment of the M13 band.  This band is used in the
derivation of the product flagging for both the triple window SST and the standard
11-micron SST product.  The impact of this is most evident at Level 3, or in products
that use this quality information (e.g. the VIIRS-SNPP GHRSST distributed by the PO.DAAC)

Users who have downloaded any of the affected VIIRS-SNPP SST products are
advised to exercise caution in using these products data for any application.
Both the OB.DAAC and the PO.DAAC have removed the affected products from
distribution.  The OBPG is in the process of regenerating these products with
corrected code.  It is recommended that users reacquire these products once
they have been regenerated.

A related note to the community:

As a result of a funding decision, NASA VIIRS SST’s have become “orphaned”
unsupported products and are not monitored to the extent they were before.
Previously, the SST group at the Rosenstiel School of Marine and Atmospheric
Science at the University of Miami were responsible for the validation,
accuracy assessment, and product quality, but ceased to be funded for VIIRS in
summer 2018. No other group was funded to maintain or validate the VIIRS SSTs.
Any questions or technical concerns should be directed to the appropriate
contacts at the OB.DAAC and the PO.DAAC.

UPDATE (21 Feb 2019):
The OBPG has competed the reprocessing of the affected data
Up Topic Announcements / Ocean Color Announcements / Recent degradation of the NASA Suomi-NPP SST product

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