• NSIDC DAAC is currently upgrading our data ingest process for NASA Earthdata Cloud. During this transition, users may notice temporary interruptions in data availability or notice small data gaps. All gaps will be resolved as quickly as possible. During this upgrade jpeg browse imagery will also not be available for preview in Earthdata search. Please reach out to NSIDC User Services with any questions or concerns.

  • On Wednesday, September 24 from 9:00 a.m. to 1:30 p.m. (US Mountain Time), this data set may not be available in the legacy data archive due to a planned system maintenance. Earthdata Cloud access will remain available for data sets that have migrated. Users of the SMAP near real-time products should use the NASA LANCE HTTPS File System for data access.

  • The NSIDC DAAC is retiring access to its legacy, on-premises data archive and transitioning to the NASA Earthdata Cloud as the primary data archive. View planned retirement dates here.

Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS, Version 4
Data set id:
NSIDC-0079
DOI: 10.5067/X5LG68MH013O
This is the most recent version of these data.
Version Summary
The NSIDC DAAC repackaged the data fields provided by GSFC in CF-compliant NetCDF files.
In this section
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Overview

This sea ice concentration data set was derived using measurements from the Scanning Multichannel Microwave Radiometer (SMMR) on the Nimbus-7 satellite and from the Special Sensor Microwave/Imager (SSM/I) sensors on the Defense Meteorological Satellite Program's (DMSP) -F8, -F11, and -F13 satellites. Measurements from the Special Sensor Microwave Imager/Sounder (SSMIS) aboard DMSP-F17 are also included. The data set has been generated using the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E) Bootstrap Algorithm with daily varying tie-points. Daily (every other day prior to July 1987) and monthly data are available for both the north and south polar regions. Data are gridded on the SSM/I polar stereographic grid (25 x 25 km) and provided in two-byte integer format. Data coverage began on 01 November 1978 and is ongoing through the most current processing, with updated data processed several times annually.
Parameter(s):
SEA ICE CONCENTRATION
Platform(s):
DMSP 5D-2/F11
DMSP 5D-2/F13
DMSP 5D-2/F8
DMSP 5D-3/F17
Nimbus-7
Sensor(s):
SMMR
SSM/I
SSMIS
Data Format(s):
netCDF-4
Temporal Coverage:
  • 1 November 1978 to present
Temporal Resolution:
  • Varies
Spatial Resolution:
  • 25 km
  • 25 km
Spatial Reference System(s):
  • NSIDC Sea Ice Polar Stereographic North
    EPSG:3411
  • NSIDC Sea Ice Polar Stereographic South
    EPSG:3412
Spatial Coverage:
  • N:
    90
    S:
    30
    E:
    180
    W:
    -180
  • N:
    -39
    S:
    -90
    E:
    180
    W:
    -180
Blue outlined yellow areas on the map below indicate the spatial coverage for this data set.

Data Access & Tools

A free NASA Earthdata Login account is required to access these data. Learn More

HTTPS File System

Get Data
Quickly download a few files using a web browser, or access data through a command-line utility such as WGET.
Related Help Resources
NASA Earthdata Cloud Data Access Guide
Type:
service

Data Access Tool

Search & Discover
Get Data
Filter files before downloading based on date, spatial area, or file name. Choose from various download options, such as Python script. Export bounding boxes as a GeoJSON.
Related Help Resources
How to filter and order from a data set web page
How to use Earthdata Download
Type: Web Application
Last updated:
View Metadata

NASA Earthdata Search

Visualize
Search & Discover
Get Data
Search and order data from all NASA DAACs using spatial and temporal filters in a map interface. Reformatting, reprojecting, and subsetting options are available for some data sets.
Related Help Resources
How to search, order, and customize data with NASA Earthdata Search
Type: Web Application

earthaccess

Get Data
Search & Discover
earthaccess is a python library to search and access NASA Earth science data with just a few lines of code.
Supported software languages:
Python
Related Help Resources
GitHub Repository
Type: Downloadable Software
Last updated:
View Metadata

Bulk Programmatic Data Access Service

Get Data
Programmatically request selected data products through NSIDC's API. Bulk download using spatial and temporal filters, or incorporate data access commands into code/scripts as needed.
Related Help Resources
Programmatic Data Access Guide
Type:
service
Last updated:
View Metadata

NASA Earthdata Cloud (AWS S3)

Get Data
Access data directly from the NASA Earthdata Cloud via Amazon Web Services Simple Storage Service (AWS S3). This access option is only available when working within the us-west-2 region and requires additional AWS S3 credentials.
Related Help Resources
NASA Earthdata Cloud Data Access Guide
AWS S3 Credentials
Type:
service
View Metadata

Panoply Data Viewer

Visualize
Analyze
Visualize georeferenced arrays in NetCDF, HDF and GRIB formats. Plot data on global or regional maps, choosing from multiple map projections. Overlay continent outlines or masks.
Type: Downloadable Software
Output Formats:
ASCII
CSV
GIF
HDF-EOS2
HDF-EOS5
HDF4
HDF5
JPEG
KML
NETCDF-3
NETCDF-4
PNG
TIFF

Documentation

Help Articles

General Questions & FAQs

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.
Read More
FAQs About NSIDC DAAC's Earthdata Cloud Migration
This article covers frequently asked questions about the NASA NSIDC DAAC's Earthdata cloud migration project and what it means to data users.
Read More
When will the legacy, on-premises archive be retired?
The NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC) is migrating its primary data access from its legacy, on-premises archive to the NASA Earthdata Cloud.
Read More

How to Articles

Filter and order from a data set web page using the Data Access Tool
Many NSIDC DAAC data sets can be accessed using NSIDC DAAC's Data Access Tool. This tool provides the ability to search and filter data with spatial and temporal constraints using a map-based interface.Users have the option to:
Read More
How do I convert NSIDC SMMR-SSM/I-SSMIS data products in polar stereographic projections from NetCDF to binary?
The NSIDC provides Python scripts for reformatting specific NSIDC SMMR-SSM/I-SSMIS data products in polar stereographic projections from NetCDF to binary.
Read More
Programmatic Access Guide for Data on daacdata.apps
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.
Read More