Data Announcements

22 March 2018

NOAA@NSIDC is pleased to announce the release of On-Ice Arctic Sea Ice Thickness Measurements by Auger, Core, and Electromagnetic Induction, From the Fram Expedition Onward. In addition to sea ice thickness, the data set provides sea ice freeboard and snow depth on sea ice from in situ measurements taken primarily using auger, coring devices, and electromagnetic (EM) sounding. When available, ice type is also included. The archive was compiled from 44 different expeditions starting with measurements from the Fram Expedition in 1894 and 1895, then to the Maud Expedition from 1922 through 1924, and continuing forward in time to observations from 2011.

The figures below give an idea of the distribution of the measurements through time and space. For about half of the more than 55,000 points at which measurements were made, the ice type is unspecified. Of the remainder, about 10% are first year ice and about 40% are multiyear... more

7 February 2018

NOAA@NSIDC has updated their September and March Sea Ice Index sea ice animations in Google Earth. The updates include adding September 2017 to the animation and updating all images to Sea Ice Index Version 3, the latest version of this data set.

To access the Google Earth files, see the NSIDC Data on Google Earth page.

4 December 2017

NOAA@NSIDC is pleased to announce the release of Version 3 Revision 1 of the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration data product. The reason for the revision change was to incorporate a new version of the input data product, Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS. Another reason was to update the data that use the SSMIS instrument to also use the SSMIS pole hole mask. In previous versions, the larger SSM/I pole hole mask was being used for these data, which was cutting out a section of valid data. In addition, this fixes a bug in the code that was causing some sections of the time series to not produce output files. Further, the data now go through 28 February 2017.

To access these data, visit the data set landing page for the NOAA/NSIDC Climate Data Record of Passive Microwave... more

20 October 2017

NOAA@NSIDC is pleased to announce the release of Sea Ice Index Version 3 (V3). V3 changes the way the monthly average area and extent data values are calculated. The way monthly average area and extent images are created remains the same as in V2.  All daily data remain the same as in V2.

The V3 method simply averages daily extent values, while the V2 method derived monthly average values from the gridded monthly-average concentration field. The change is in response to questions about what seemed to be an inconsistency between daily and monthly values. When users summed daily values, and then divided by number of days in a month to get a monthly average value, that number was different, and sometimes quite different, from the monthly average numbers we presented. Both the V2 and V3 methodologies are valid and defensible ways of representing passive microwave-derived sea ice concentration data, but the goal of this change... more

23 August 2017

NOAA@NSIDC is pleased to announce the release of Version 3 of the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration (final CDR). The reason for the version change is to update the masks used to remove spurious ice in the Northern Hemisphere. The masks changed from sea surface temperature climatology-based masks to the Polar Stereographic Valid Ice Masks Derived from National Ice Center Monthly Sea Ice Climatologies. These masks are used for most passive microwave-based sea ice products at NSIDC. See the NSIDC news announcement, Newly Available Valid Ice Masks Depend on Operational Ice Center Analyses, for more.

In addition, a Near-Real-Time NOAA/NSIDC Climate Data Record of Passive Microwave Sea... more

9 May 2017

In an effort to continue to make the Sea Ice Index a user friendly, go-to source for sea ice information, NOAA@NSIDC has added the median sea ice extent line to the daily and monthly Sea Ice Index concentration images. Previously, this line only appeared on the daily and monthly sea ice extent images. The addition of the median extent line to the concentration images helps to inform users of how sea ice extent and concentration relate to one another. To see these, and all other Sea Ice Index images, visit the Sea Ice Index web site.

Data Set DOI:

3 May 2017

NOAA@NSIDC is pleased to announce that the Google Earth animation for the maximum annual Arctic sea ice extent has been updated. The March 2017 maximum has been added to the time series in the KMZ file. To view these, and other, Google Earth files, visit the NSIDC Data on Google Earth web page.

1 May 2017

NOAA@NSIDC is pleased to announce that the Unified Sea Ice Thickness Climate Data Record, 1947 Onward has been updated with data through 01 January 2017 and now also contains Antarctic data. This climate data record is the result of a concerted effort to collect as many observations as possible of Arctic and Antarctic sea ice draft, freeboard, and thickness and to format them consistently with clear documentation, allowing the scientific community to better utilize what is now a considerable body of observations. Thanks to Axel Schweiger and Ron Lindsay of the Polar Science Center Applied Physics Laboratory at the University of Washington for supplying these data.

Data Set DOI:

26 April 2017

NOAA@NSIDC is pleased to announce the release of the Sea Ice Index in GeoTIFF format. GeoTIFF files are available for both concentration and extent data for both hemispheres at daily and monthly resolutions. The daily and monthly GeoTIFF files provide the Sea Ice Index concentration and extent data in a georeferenced format. The GeoTIFF images are single band images with an embedded color table to make visualizations of the dataset in GIS programs as easy as possible. To learn more and to access these data, visit the Sea Ice Index data set web page.

Data Set DOI:

4 April 2017

NOAA@NSIDC is pleased to announce that we have created and released 1 km latitude and longitude grids that correspond to the 1 km ASCII data files in the IMS Daily Northern Hemisphere Snow and Ice Analysis at 1 km, 4 km, and 24 km Resolutions data set. For more information and to access these files, see the Lat/Lon Grids section of the IMS user guide.

Data Set DOI: