The images and data are provided courtesy of:
Fetterer, F., K. Knowles, W. Meier, and M. Savoie. 2002, updated 2009. Sea Ice Index, 1979 – 2009. Boulder, Colorado USA: National Snow and Ice Data Center. Digital media.
You can gain access to an interactive tool to display these graphs, direct from NSIDC by visiting
The Browse Image Spreadsheet Tool to compare the extent and concentration trends
Monthly Sea Ice Extent and Concentration Trends Least squares regression is used to calculate the trend in ice concentration for that month at each roughly 25 km data cell. If no trend is detectable at a 95% confidence level, the data cell is white.