Data Set ID:

Sea Ice Trends and Climatologies from SMMR and SSM/I-SSMIS, Version 3

NSIDC provides this data set to aid investigations of variability and trends in sea ice cover. Ice cover in these data are indicated by sea ice concentration: the percentage of the ocean surface covered by ice. The ice-covered area indicates how much ice is present; it is the total surface area of a pixel multiplied by the ice concentration in that pixel. Ice persistence is the percentage of months over the data set time period that ice existed at a location. The ice extent indicates whether ice is present; here, ice is considered to exist in a pixel if the sea ice concentration exceeds 15 percent. This data set provides users with data about total ice-covered areas, sea ice extent, ice persistence, and monthly climatologies of sea ice concentrations.

This is the most recent version of these data.

Version Summary:

Changes to this version include: 

  • Incorporated a change from Version 2 to Version 3 of the Bootstrap data set. For V3 Bootstrap data, the concentration record was re-calculated for the entire period of the data set, 1978 through current processing. The most impactful changes were a lowering of the threshold to 10% for ice extent, and the recalculation of the algorithm’s tie points every day. However, despite the new 10% threshold for Bootstrap input data, this Sea Ice Trends and Climatologies data set continues to be derived using a 15% threshold.

COMPREHENSIVE Level of Service

Data: Data integrity and usability verified; data customization services available for select data

Documentation: Key metadata and comprehensive user guide available

User Support: Assistance with data access and usage; guidance on use of data in tools and data customization services

See All Level of Service Details

Data Format(s):
  • PNG
  • Binary
  • JPEG
Spatial Coverage:
N: 90, 
N: -39.23, 
S: 30.98, 
S: -90, 
E: 180, 
E: 180, 
W: -180
W: -180
Platform(s):DMSP 5D-2/F11, DMSP 5D-2/F13, DMSP 5D-2/F15, DMSP 5D-2/F8, DMSP 5D-3/F17, Nimbus-5, Nimbus-7
Spatial Resolution:
  • 25 km x 25 km
Temporal Coverage:
  • 26 October 1978 to 31 December 2020
Temporal ResolutionVariesMetadata XML:View Metadata Record
Data Contributor(s):Stroeve, J. and W. N. Meier.

Geographic Coverage

Once you have logged in, you will be able to click and download files via a Web browser. There are also options for downloading via a command line or client. For more detailed instructions, please see Options Available for Bulk Downloading Data from HTTPS with Earthdata Login.

As a condition of using these data, you must cite the use of this data set using the following citation. For more information, see our Use and Copyright Web page.

Stroeve, J. and W. N. Meier. 2018. Sea Ice Trends and Climatologies from SMMR and SSM/I-SSMIS, Version 3. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].

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How To

How do I import sea ice data binary data files into ArcGIS?
The following are instructions describing how to import sea ice binary files into ArcGIS. These instructions were tested with ArcMap 10.5 and 10.6. 1. Rename the Data File. In order to be able to import a Polar Stereographic sea ice concentration file into ArcGIS, you will need to: Rename the... read more
V0 Programmatic Data Access Guide
Data from the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) can be accessed directly from our HTTPS file system. We provide basic command line Wget and curl instructions for HTTPS file system downloads below. For questions about programmatic access to NSIDC... read more


Descriptions of and Differences between the NASA Team and Bootstrap Algorithms
NSIDC currently archives passive microwave sea ice concentration products based on two algorithms: the NASA Team algorithm and the Bootstrap algorithm. Both algorithms were developed by researchers at the NASA Goddard Space Flight Center in the 1980s. Provided below are two short summaries of the... read more