evidence: Daily Sea Ice Extent Time Series The monthly Sea Ice Index provides a quick look at Antarctic-wide changes in sea ice. It is a source for consistently processed ice extent and concentration images and data values since 1979. Monthly images show sea ice extent with an outline of the 30-year (1981-2010) median extent for that month (magenta line). Other monthly images show sea ice concentration and anomalies and trends in concentration. The daily Sea Ice Index provides a quick look at Antarctic-wide changes in sea ice. It provides consistently processed daily ice extent and concentration images and data since 1979. Daily extent images show ice extent at concentrations greater than 15% for a given day with an outline of the typical extent for that day based on a 30-year (1981-2010) median (orange line).