NASA Distributed Active Archive Center (DAAC) at NSIDC

Sea Ice Data

Sea Ice Data from a Variety of Sensors and Sources

Tools

NSIDC provides software tools to extract and geolocate sea ice data in the polar stereographic projection derived from passive microwave instruments, as well as masking tools that limit the influence of weather effects on sea ice concentrations.

Note: Tools for accessing the trends and climatologies, the visible and infrared, and the field observation data are available from the documentation for each data set. See the Data Summaries Web pages for links to the documentation.

These tools work with the following passive microwave sea ice data sets:

All tools are available via FTP and are grouped into the following categories:



Display Tools

The data tools allows the user to display data from the data files in various ways. The data display tools that are available are the following:

Tool Name dataviewer.tar.gz 
Applicable Data Sets
Polar Stereographic Projection
Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures
DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures
Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Sea Ice Concentrations
Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS
Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data
AMSR-E/Aqua Daily L3 25 km Brightness Temperature & Sea Ice Concentration Polar Grids

EASE-Grid Projection
Near-Real-Time SSM/I-SSMIS Pathfinder Daily EASE-Grid Brightness Temperatures
DMSP SSM/I-SSMIS Pathfinder Daily EASE-Grid Brightness Temperatures
Nimbus-7 SMMR Pathfinder Daily EASE-Grid Brightness Temperatures
AMSR-E/Aqua Daily EASE-Grid Brightness Temperatures
Northern Hemisphere EASE-Grid 2.0 Weekly Snow Cover and Sea Ice Extent Version 4

Quarter-Degree Projection
AMSR-E/Aqua Daily Global Quarter-Degree Gridded Brightness Temperatures
Description The NSIDC DataViewer is an interactive tool for viewing and displaying satellite images from select NSIDC passive microwave data sets. Images in PNG, JPEG, TIFF, and other commonly used image data formats can also be viewed and displayed in a user-defined grid.

Up to 64 images can be displayed simultaneously in the DataViewer resizeable graphics window, allowing data users to page through a series of images. Images can be scaled and manipulated either individually or as a group. By moving the cursor over an image, a data user can obtain the latitude and longitude coordinates as well as the image value at the cursor location. After an image or series of images is manipulated, the contents of the graphics window(s) can be saved in a variety of image formats, including PostScript, PNG, JPEG, and TIFF.

The DataViewer is a program written in Interactive Data Language (IDL). It can be run in IDL with an IDL license, via the freely distributed IDL Virtual Machine, or as a run-time application.

Please Note:
  • DataViewer produces a scaling error with time values in DMSP-F17 SSMIS time (.tim) files. When using SSMIS .tim files, please be advised that data points will display as 1/10th of their actual value.
  • DataViewer is currently incompatible with data obtained using the Polaris search and subsetter tool.
Access FTP



Tool Name display_onset_of_melt.pro
Applicable Data Sets Snow Melt Onset Over Arctic Sea Ice from SMMR and SSM/I-SSMIS Brightness Temperatures
Description IDL program that allows the user to view the data in graphical form.
Access FTP



Extraction Tool

The following data extraction tool allows the user to extract and read the data from the data files:

Tool Name extract_ice.pro
Applicable Data Sets Nimbus-5 ESMR Polar Gridded Sea Ice Concentrations
Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I Passive Microwave Data
Bootstrap Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I
Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Sea Ice Concentrations
Description IDL program that extracts a time series of polar sea ice data. The extraction routine works on both the daily and monthly sea ice files allowing users to select and display sea ice concentrations. For monthly data, users may select which image threshold to view (0, 5, 10, or 15% ice cut off).
Access FTP
Usage Example IDL Routines for Passive Microwave Data: Usage Examples - extract_ice.pro



Geocoordinate and Pixel-Area Tools

The geolocation and pixel-area tools described here provide the same functionality for all polar stereographic passive microwave sea ice data sets at NSIDC. See the Polar Stereographic Geocoordinate and Pixel Area Tools Web page for information.




Masks

Ocean Masks

The ocean masks are applicable to the following data sets: Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I-SSMIS Passive Microwave Data, and Sea Ice Trends and Climatologies from SMMR and SSM/I-SSMIS. Please see the Ocean Masks from NSIDC Web page for a description of ocean masks.

Land masks

The land mask, coastline, and latitude/longitude line files described here can be used for all polar stereographic passive microwave sea ice data sets at NSIDC. See the Polar Stereographic Data Masks and Overlays Web page for information.