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Data Set ID:

Near-Real-Time SSM/I-SSMIS EASE-Grid Daily Global Ice Concentration and Snow Extent, Version 4

Notice (04/21/2016): On 04/05/2016 a change in the solar panel position to shade the nitrogen tank on board the Defense Meteorological Satellite Program (DMSP) F-17 satellite was made. In doing so, the integrity of the vertically polarized 37 GHz channel (37V) of the Special Sensor Microwave Imager and Sounder (SSMIS) was compromised. This is a primary channel used in the NISE processing. On 04/13/16 an additional change in the solar panel position was made. This change had improved the problems we were seeing in the 37V GHz channel for data from April 13 to April 19; however, on April 20, the 37V GHz channel started to produce bad data again. Thus, data from April 20 onward should not be used until further notice.

The Near-real-time Ice and Snow Extent (NISE) data set provides daily, global maps of sea ice concentrations and snow extent. These data are not suitable for time series, anomalies, or trends analyses. They are meant to provide a best estimate of current ice and snow conditions based on information and algorithms available at the time the data are acquired. Near-real-time products are not intended for operational use in assessing sea ice conditions for navigation.

Version Summary:
  • Updated metadata field values for PGEVERSION (collection level remains
    Version 4)

  • Removed 15% sea ice concentration threshold that assigned pixels
    with a sea ice concentration of <15% as ocean (data value of 255)

  • Reprocessed NISE Version
    4 to include sea ice concentration values of 1-14%

This revision is an update to NISE Version 4. All
Version 4 data (17 August 2009 - present) have been reprocessed
with this system.

Geographic Coverage

Spatial Coverage:
  • N: 90, S: -90, E: 180, W: -180

Spatial Resolution: Not Specified
Temporal Coverage:
  • 4 May 1995
Temporal Resolution: 1 day
  • Sea Ice > Ice Extent
  • Snow/Ice > Ice Extent
  • Sea Ice > Sea Ice Concentration
  • Snow/Ice > Snow Cover
Platform(s) DMSP 5D-2/F13, DMSP 5D-3/F17
Sensor(s): SSM/I, SSMIS
Data Format(s):
Version: V4
Data Contributor(s): Anne Nolin, Richard Armstrong, Jim Maslanik

Data Citation

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.

Nolin, A. W., R. Armstrong, and J. Maslanik. 1998. Near-Real-Time SSM/I-SSMIS EASE-Grid Daily Global Ice Concentration and Snow Extent, Version 4. [Indicate subset used]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. doi: [Date Accessed].
No technical references available for this data set.


Do you have code for reading NISE data into MATLAB, IDL, Python, or NCL?

The HDF Group has example code for access and visualization of NISE data in MATLAB, IDL, Python, and NCL.