About these plots - Change in daily Southern Hemisphere (Antarctic) sea ice extent:
This is a plot of the change in daily total Southern Hemisphere sea ice extent for the most recent 12 month period. Hence, if yesterday's Southern Hemisphere sea ice extent was 17.5 million square kms and today it is 17.2 then the change in daily extent is -300,000 square kms. The plot is updated daily. See the data here.Data are from the National Snow and Ice Data Center and are based on concentrations from Nimbus-7 SMMR and DMSP SSM/I Passive Microwave Data.