Data Announcements

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 is to simply average of 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... 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 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:

19 January 2017

NOAA@NSIDC is pleased to announce the release of Sea Ice Index Version 2.1. The motivation for the update to Version 2.1 was to port the Sea Ice Index IDL code to Python. Prior to V2.1, the Sea Ice Index was processed with code written mainly in IDL with some Perl, Ruby, and C. In an effort to streamline the processing, all of the code has been ported to Python. Major improvements include a new color scheme for the daily and monthly images and graphs, reorganized FTP site, daily images and blue marble images now archived on FTP, minor adjustments to monthly computations, and interdecile and interquartile columns now supplied in the daily climatology file to compliment the standard deviation value in that file. To see the new the new images and graphs, visit the Sea Ice Index web site. For complete details on all the updates in V2.1, please read the see the Sea... more

9 January 2017

NOAA@NSIDC would like to alert users of an upcoming update to the Sea Ice Index FTP directory structure and file names. The current FTP directory  ( contains monthly data and images directly under the top-level directory with one subdirectory for each month. The monthly subdirectories house both northern and southern hemisphere data files and images within them (Figure 1). Beginning 18 January 2017, all Sea Ice Index data will be organized by hemisphere at the top level, then parsed by temporal resolution, daily or monthly, and organized further by file type: tabulated data, browse images, or Shapefiles (Figure 2). In addition, the product is being versioned up to version 2.1, so all file names will have v2.1 in the file name instead of v2 only. If you have any scripts that access Sea Ice Index data, you will need to update them with the new file names and... more

15 December 2016

At the American Geophysical Union annual fall meeting this week in San Francisco, NOAA released their 2016 Arctic Report Card. The Arctic Report Card, now in its 11th year, is the work of 61 scientists from 11 nations who report on air, ocean, land, and ecosystem changes. Find visual highlights from the report in NOAA’s 2016 Arctic Report Card: Visual highlights article at

Along with the extraordinarily warm Arctic this fall and winter, the record low ice extents for this time of year in both hemispheres are making the news. Another article, Global sea ice in November: Black swans flock to both poles, has the... more

14 December 2016

NOAA@NSIDC is pleased to announce the release of the Sea Ice Mass Balance in the Antarctic (SIMBA) data set. This data set provides different measurements of Antarctic sea ice collected as part of the SIMBA program. The observation program was carried out in the fall of 2007 and the spring of 2009 during a drift program of the Nathaniel B. Palmer icebreaker along with a buoy network established on the Antarctic sea ice. Measurements of ice thickness, temperature profiles, large-scale deformation, and other sea ice characteristics were made. To learn more and to access these data see the Sea Ice Mass Balance in the Antarctic (SIMBA) data set page.

Data Set DOI:

11 November 2016

NOAA@NSIDC is pleased to announce that the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration, Version 2 data set is now available through 2015. This data set provides a Climate Data Record (CDR) of sea ice concentration from passive microwave data. It provides a consistent, daily and monthly time series of sea ice concentrations from 09 July 1987 through 2015 for both the north and south polar regions on a 25 km x 25 km grid.

Data Set DOI:

25 August 2016

NOAA@NSIDC is pleased to announce that the Google Earth animation for the maximum annual Arctic sea ice extent has been updated. The March 2016 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.

15 August 2016

NOAA@NSIDC is pleased to announce the addition of 1,173 photographs to the Glacier Photograph Collection. This addition is a special collection that contains photographs of glaciers in and around the Lake Clark National Park and Preserve in Alaska, USA. The collection was compiled by a Natural Resource Specialist Intern in the GeoSpatial Services Department at Saint Mary’s University, MN. The collection is comprised of many images of glaciers in and around the park and preserve taken from both the air and the ground from 1987 through 1990 and in 2004 and 2007. To view the new collection, visit the Glacier Photograph Collection search interface and select “Lake Clark National Park Glacier Photographs” from the Choose a Collection drop-down list.

Data Set DOI: http... more

19 July 2016

Until now, climate diagnostic applications, reanalyses, and atmospheric modeling studies that needed a lower boundary condition did not have an arctic-wide gridded ice concentration data set to use based on observations and one that extends back as far as the mid-nineteenth century. Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward addresses this need by improving and extending the Arctic and Southern Ocean Sea Ice Concentrations product. It does this by adding newly available historical sources and by using the NOAA/NSIDC Climate Data Record of Passive Microwave Sea Ice Concentration for the satellite era.

The NOAA@NSIDC product, Gridded Monthly Sea Ice Extent and Concentration, 1850 Onward, uses the following data sources:

  • North Atlantic ice edge positions covering 1850... more
6 July 2016

NOAA@NSIDC is pleased to announce the release of Sea Ice Index Version 2. Improvements include using the most recently available version of the Goddard Space Flight Center (GSFC) input sea ice concentration data and revising three computations in the Sea Ice Index processing code. The new GSFC data have undergone additional manual quality control procedures at the GSFC that go farther to remove spurious ice. The GSFC data are available as their own data set from the NSIDC DAAC as Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data. The other three updates adjust calculations present in the old Sea Ice Index processing code that were in need of improvement. Because of these updates, minor changes in some of the ice extent and area numbers can be seen with the average change in the trends over all 12 months being on the order of 0.05 percent/decade (approximately 500 sq. km/year). For a complete... more

28 June 2016

An improved version of the Sea Ice Index is coming.  On Wednesday, 6 July 2016, Sea Ice Index Version 2 will be released. It will look and act the same as Version 1, but will have updated processing code and will use a new version of the input data. Because of these updates, minor changes in some of the ice extent and area numbers will be seen. These will be clearly described in the documentation, which will also be updated on 6 July.

We are alerting users to this impending update because file names will change. Any scripts that automatically download Sea Ice Index data each day will need to be updated to reflect this file name change. The new file names will have a “_v2” appended to the end of the file name such as N_04_area_v2.txt and N_04_plot_v2.png.

Further, NOAA@NSIDC has received support from the NOAA Big Earth Data Initiative (BEDI) program to create web services built around the Sea Ice Index. This will provide a simple HTTP interface for requesting geo-... more

14 June 2016

On 05 April 2016, the vertically polarized 37 GHz (37V) channel of the SSMIS instrument on the DMSP-F17 satellite began yielding compromised brightness temperature data. This channel is one of those used to estimate sea ice concentration shown in the Sea Ice Index, so data processing was temporarily suspended.

NOAA@NSIDC is pleased to announce that, today, Sea Ice Index processing has resumed and the time series now uses the SSMIS instrument on the DMSP-F18 satellite beginning 01 April 2016. These sea ice concentration values come from the NSIDC Near-Real-Time DMSP SSMIS Daily Polar Gridded Sea Ice Concentrations product. Prior to transitioning this near-real-time data set to the F18 SSMIS instrument, NSIDC investigated whether or not algorithm parameters would need to be calibrated to minimize the difference between sea ice extents derived from F17 and F18.

Because each sensor and spacecraft orbit is slightly different,... more

3 May 2016

The Sea Ice Index is typically updated every day to display yesterday’s ice extent for both hemispheres. The Index relies on data that come from the DMSP F17 satellite. However, these data have not been reliable since early April; so the NOAA@NSIDC team has not been able to update the Sea Ice Index since 31 March 2016.

Sea Ice Index processing uses an NSIDC NASA DAAC product, Near-Real-Time DMSP SSMIS Daily Polar Gridded Sea Ice Concentrations (NSIDC-0081), as input. The NSIDC DAAC has started the work needed to move to a new source for NSIDC-0081. This involves retrieving F18 and F16 satellite brightness temperatures from our data providers and then implementing parallel processing for ice concentration. The F18 satellite will be the primary replacement for F17, but should that satellite fail, we will be able to switch to F16 without a service interruption.

An interim version of the NSIDC-0081 data stream will be used... more

15 February 2016

NOAA@NSIDC is pleased to announce that the International Ice Patrol (IIP) has updated their Iceberg Sightings Database through the 2015 iceberg season. The IIP has been collecting information on iceberg activity in the North Atlantic since 1913, and this database contains data from these sightings starting in 1960. The IIP data files include latitude and longitude of sighted icebergs, coded iceberg size and shape class, and date and time of the sighting. For more information on this data set and to access the data, please visit the International Ice Patrol Iceberg Sightings Database web page.

Data Set DOI:

4 February 2016

Fifty years ago today, the first satellite in the NOAA Environmental Science Services Administration (ESSA) series of satellites, ESSA-1, acquired its first image. The image was of Antarctica. Now, NSIDC’s Garrett Campbell and David Gallaher are attempting to organize the rescue of data from the satellite. They hope to use the recovered imagery to locate the position of the southern hemisphere’s sea ice edge, as was possible after rescuing infrared imagery from the early NASA NIMBUS series.

It won’t be easy to rescue the ESSA-1 data. According to the book Satellite Remote Sensing of the Polar Regions: Application, Limitations, and Data Availability, limitations of the imagery include “coarse ground resolution obscured by cloud and fog. Inoperative in darkness. Often difficult to distinguish ice from cloud. Imagery from the early meteorological satellites was not coupled to detailed... more

11 January 2016

Arctic Matters Day is a free public program that will be held 14 January 2016 at the National Academy of Sciences building in Washington, DC. It will provide an overview of the dramatic environmental changes affecting the Arctic region and the ways that these changes can potentially affect the entire planet. If you are in the Washington D.C. area, consider attending the free public program, Arctic Matters Day. Through exhibits and talks, the program will “explore how many facets of our lives (for instance, our coastlines, our weather, our fish supplies, and our security) are tied to what is happening in that ‘isolated’ part of the world.”

Two NOAA@NSIDC data sets, the Sea Ice Index and the Multisensor Analyzed Sea... more

8 January 2016

The Glacier Photograph Collection, managed by NOAA@NSIDC, will get a big boost in 2016 from a Council on Library and Information Resources (CLIR) grant. The Glacier Photograph Collection includes over 15,000 digital images available online, as well as an analog collection of photographic prints of glaciers from around the world beginning in the mid-1850s. This grant begins a collaboration between NSIDC and the Digital Library at the University of Colorado at Boulder (CU). The grant will allow for a dedicated archivist and graduate assistants to digitize, describe, and publish the approximately 9,000 remaining photographic prints that have not yet been scanned, described, and entered into the searchable online catalog.

The online portion of the collection now consists of both a relatively small collection of born-digital photos and a large... more