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These articles provide answers to frequently asked questions related to Earth's frozen realms. Questions range from general background information and detailed science processes to the data gathered and archived at the National Snow and Ice Data Center (NSIDC) and its data management programs including NOAA@NSIDC, the NASA NSIDC Distributed Active Archive Center (DAAC), and the Exchange for Local Observations and Knowledge of the Arctic (ELOKA). If you have a question that is not answered here, please contact NSIDC User Services.


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Charctic screenshot taken November 2022
NSIDC scientists use the 1981 to 2010 average of sea ice concentration and extent to have a consistent basis for comparison to today’s fluctuating conditions. The 30 years observed in this baseline provide enough data to even out short-term
By Michon Scott Freshly formed sea ice can be as thin as a few sheets of paper or as thick as a one-story house, depending on how long it has existed. Measuring sea ice thickness is harder than measuring how much sea ice covers the ocean surface. No
Hurricane Fiona heads north
Hurricanes form in the tropics, feeding on very warm ocean waters. As they track northward, they may transform to an extratropical storm with an added punch, sometimes reaching southern Greenland, Alaska, and even Arctic latitudes of the North Atlantic.
Sea ice concentration on globe
NSIDC archives satellite data for polar sea ice dating back to November 1978. As public interest in sea ice has grown, NSIDC has published regular updates on sea ice conditions in Arctic Sea Ice News & Analysis. The sharpest declines have occurred in
About 70 percent of the planet’s freshwater is locked up in ice sheets: massive ice bodies spanning more than 50,000 square kilometers (20,000 square miles). Our planet has two ice sheets, one covering roughly 80 percent of Greenland and the other