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January 2014: the OSI SAF sea ice production back to operational status

The switch to SSMIS data made in January 2013 has now been fully validated and reviewed. The main conclusion is that the quality of the OSI SAF sea ice products with SSMIS is similar or better than with SSM/I. Hence, the OSI SAF sea ice products are now labelled operational again.

January 2013: the sea ice production switches from SSM/I (F15) to SSMIS (F17)

As the SSMI data received at OSI SAF has been corrupted since 18 January 2013, we have chosen to switch to SSMIS data for the operational OSI SAF sea ice products. The use of SSMIS data for sea ice production have been tested for some time, but is not yet fully validated. Still, the tests so far has shown that the difference between using SSMI and SSMIS has only a small impact on the products. The OSI SAF sea ice products are therefor labelled pre-operational until a full validation has been performed.

Below are some comparison maps (difference SSM/I - SSMIS) for sea ice concentration in the Northern Hemisphere for 15, 16, and 17 January 2013. They show difference between SSM/I and SSMIS sea ice concentration for the northern hemisphere. Shades of blue (red) delineate area where the new SSMIS data is processed into lower (higher) sea ice concentraion values.

Comp SIC 15.01
(a - 15.01.2013)
Comp SIC 16.01
(b - 16.01.2013)
Comp SIC 17.01
(c - 17.01.2013)
Comparison images for SIC from SSM/I - SSMIS for 3 days in January 2013
Click on each image for accessing a larger version.

The maps above clearly indicate that most of the differences between the two ice concentration fields occur along the ice edge, that is for sea ice values between 15% and 80%. Inside the ice pack, and out in open waters, there is basically no difference.

The products based on SSMIS seems to be performing at least as good as those based on SSM/I. Updated validation statistics are available here:
http://osisaf.met.no/validation/val_greenland.html.
Select the "last quarter" plots. The validation graphs are based on SSMIS after 19.February 2013, and on SSM/I before this date.

   
       
     

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