The animations include data from four different satellites. Data from the Nimbus-7 satellite were used for the period October 1978 to July 1987. DMSP F8 data were used from August 1987 through December 1991. Data from the DMSP F11 satellite were used from January 1992 until September 1995. Data for the remaining 16 months are from the DMSP F13 satellite.
Several differences exist between the two tools.
The animations show ice concentration variation for the entire study period. The animations were built using a free program called gifmerge . The Arctic animation contains 4145189 bytes and the Antarctic animation contains 4607857 bytes. They cover the period October 1978 to December 1996, giving them a length of 219 frames. The animations can be displayed on nearly all web browsers and are constructed to loop infinitely with a dwell time of 0.5 seconds.