Sea ice concentration data from NASA Goddard based on SSMI and NASA Team (NT2) algorithm

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Sea ice concentration data from NASA Goddard based on SSMI and NASA Team (NT2) algorithm
Main content

The NASA Team 2 (NT2) / SSMI data set of Arctic and Antarctic sea ice concentration is available at daily timesteps and 25km spatial resolution for 1992-2008. NT2, an extension of the original NASA Team algorithm, uses SSMI 85GHz channels to help resolve ambiguity between low ice concentrations and areas with strong surface effects (due to snow layering and glazing). 85GHz channels introduce more weather contamination. NT2 implements a radiative transfer model to filter for weather that simulates brightness temperatures under several idealized polar atmospheres. The algorithm searches for the best fit between the observed and modeled brightness temperature ratios to pick the final concentration. Sea ice from NT2 is more similar to Bootstrap sea ice than was the original NASA Team sea ice. Some differences are still apparent; NT2 usually shows slightly higher concentrations in the Antarctic and more sensitivity to thin ice. This data set overlaps with those using the same satellite data but different algorithms, including the Goddard/NSIDC Bootstrap and NASA Team data sets, facilitating useful comparisons that can serve as a measure of uncertainty.

Key Strengths

Key Strengths

Addresses weaknesses of the original NASA Team algorithm, especially with regards to sensitivity to emissivity variations. This leads to significant improvement in the Antarctic.

Key Limitations

Key Limitations

Potential sensitivity of NT2 to weather effects as it uses the 85GHz channel

Short period of record

Please cite data sources, following the data providers' instructions
Dataset DOIs
Hosted Climate Index Files
Usage Restrictions

Cite this page

Acknowledgement of any material taken from or knowledge gained from this page is appreciated:

National Center for Atmospheric Research Staff (Eds). Last modified "The Climate Data Guide: Sea ice concentration data from NASA Goddard based on SSMI and NASA Team (NT2) algorithm.” Retrieved from on 2024-04-17.

Citation of datasets is separate and should be done according to the data providers' instructions. If known to us, data citation instructions are given in the Data Access section, above.

Acknowledgement of the Climate Data Guide project is also appreciated:

Schneider, D. P., C. Deser, J. Fasullo, and K. E. Trenberth, 2013: Climate Data Guide Spurs Discovery and Understanding. Eos Trans. AGU, 94, 121–122,

Key Figures

Arctic sea ice: SSMI / NT2

Average sea ice concentration for March 2003-2007 according to the Goddard NT2 / SSMI data set. (Figure by D. Schneider)

Other Information

Earth system components and main variables
Dataset collections

Years of record
Data time period extended
No, data set not being extended
Input Data

SSMI: multiple channels

Vertical Levels:
Missing Data Flag
Missing data present
Ocean or Land
Ocean Only
Spatial Resolution

25 x 25 km

Model Resolution (reanalysis)
Data Assimilation Method
Model Vintage (reanalysis)

Key Publications
Not available...