| Northern Hemisphere | Southern Hemisphere | |
| Legend | ||
| ocean | land | ice sheet | snow | sea ice (low concentration to high concentration) |
||||
About the Image and Data. The image is processed from the Near-Real-Time SSM/I-SSMIS EASE-Grid Daily Global Ice Concentration and Snow Extent product (Near-Real-Time Ice and Snow Extent, NISE), which generates a near-real-time map of sea ice concentrations and snow extent in both the Northern and Southern Hemispheres. The NISE product is created using passive microwave data from the Defense Meteorological Satellite Program (DMSP) F13 Special Sensor Microwave/Imager (SSM/I). Snow extent and sea ice concentration maps are provided in two 25-km azimuthal, equal-area projections, the NSIDC Southern Hemisphere 25-km resolution and Northern Hemisphere 25-km resolution EASE-Grids (see All About EASE-Grid). NISE data and GIF browse files are updated daily and are available for two weeks after initial posting.
About the Images and Data. The images above show sea ice concentration in a polar stereographic projection. They are produced from the Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Sea Ice Concentration product. NSIDC applies the NASA Team algorithm near-real-time brightness temperatures provided by the Marshall Space Flight Center from the Defense Meteorological Satellite Program (DMSP) F13 Special Sensor Microwave/Imager (SSM/I). These brightness temperatures have not received the same types of quality control that are applied to our "standard" sea ice data set, the DMSP SSM/I Daily and Monthly Sea Ice Concentration Grids for the Polar Regions.
The Near-Real-Time DMSP SSM/I-SSMIS Daily Polar Gridded Sea Ice Concentration data are updated daily and are typically available within 1-2 days following the time of SSM/I image acquisition. They will be retained on the ftp site until NSIDC's standard sea ice product becomes available.
Sea ice concentration refers to the fraction of ice within each image pixel. The images are color-coded to show varying levels of ice concentration for the Northern and Southern Hemispheres. Grey represents land. Shades of blue represent low concentration, and shades of purple represent high concentration. Pixels with at least 15% concentration are classified as sea ice. Pixels with less than 15% ice concentration are classified as water.
For a discussion of the relationship between sea ice concentration and climate change, please visit State of the Cryosphere.
| Cryospheric Climate Indicators in the
Arctic and the Sea Ice Index |
| Cryospheric time series images characterize the changes that are occurring, while putting changes in a spatial and historical context. For details, see Cryospheric Climate Indicators in the Arctic. |
Contact Us | NSIDC Web Policy | Use & Copyright | Our Sponsors
Supporting Cryospheric Research Since 1976
449 UCB University of Colorado Boulder, CO 80309-0449
