Introduction

Soil Temperature

Alaska

Russia

Snow Cover

Snow Off Day

Sea Ice Index

Monthly Sea Ice Images

Daily Sea Ice Images

Browse & Compare Images

Archived Data & Images

Image Derivation

Interpretation Resources

Sea Ice Index: Download Archived Data and Images

Here you can access the Sea Ice Index archives of images and data in various formats.

Animated Images

Animate a series of images of extent, concentrations, anomalies, trends, or plots over a specified period of time.

Get Extent and Concentration Data

Data files tabulate extent and area (in millions of square kilometers) by year for a given month. For example, the file "N_04_area.txt" contains data from the Northern Hemisphere for the month of April.

Get Extent and Concentration Images

Image files are available. For example, the file "S_200303_anom.png" is an image of concentration anomalies in the Southern Hemisphere in March 2003.

Get GIS Compatible Files (shapefiles)

Monthly sea ice extent shapefiles, November 1978 to present. Shapefiles are available for Northern and Southern hemispheres, both polygons and polylines.

Monthly median shapefiles. Each month's shapefile indicates that month's median extent for the period 1979 to 2000. Shapefiles are available for Northern and Southern hemispheres, polylines only.

Shapefiles are organized in monthly directories, by extent for that month and year or by median extent for that month. Files are zipped. For example, "extent_N_199806_polyline.zip" contains the polyline extent shapefile for the Northern Hemisphere for June 1998.

Get Passive Microwave Ice Concentration Data

The Sea Ice Index is derived from Sea Ice Concentrations from Nimbus-7 SMMR and DMSP SSM/I Passive Microwave Data and Near Real-Time SSM/I Polar Gridded Sea Ice Concentrations (NRTSI).