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Research Collaborations that Matter
Across the planet, snow and ice play a vital role in regulating Earth’s climate and providing freshwater resources to people, plants, and animals. That's why we study it.
Secure Stewardship of NASA, NOAA, and NSF Data
We archive and distribute scientific data from Earth-observing satellites, airborne remote sensing campaigns, field studies and historical observations.
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When the temperature of the ground drops below 0° Celsius (32° Fahrenheit), it becomes frozen ground. Permafrost is a permanently frozen layer below Earth’s surface. It consists of soil, gravel, and sand, usually bound together by ice.
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Glaciers are huge masses of ice, snow, rock, sediment, and often liquid water that originate on land and move down slope under the influence of their own weight and gravity. The two main types are continental glaciers (or ice sheets) and alpine glaciers.
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Ice sheets are masses of glacial land ice extending more than 50,000 square kilometers (20,000 square miles). There are only two ice sheets worldwide today, the Antarctic and Greenland ice sheets. They contain more than 99 percent of the land ice on Earth.
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An ice shelf is a large floating platform of ice that forms where a glacier or ice sheet flows down to a coastline and onto the ocean surface. Ice shelves play an important role in slowing the flow of ice from glaciers or ice sheets into the ocean. When ice shelves collapse, research has shown that glaciers accelerate, flowing into the ocean and adding to sea level rise.
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Sea ice is frozen seawater that floats on the surface of polar oceans and seas. It grows during each hemisphere’s winter; and it retreats in the summer, but does not completely disappear. The highly reflective white surface of sea ice reflects solar energy, cooling the planet. When it melts, the darker ocean absorbs more heat, reinforcing the cycle of melting sea ice.
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Snow is composed of frozen water crystals. It is not frozen rain, but a crystallization of ice that typically forms in clouds. Highly reflective, white snow bounces solar energy back into space instead of warming the planet. Mountain snowpacks also provide a slow release of fresh water into rivers and waterways.
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Soil moisture is the water content of soil and is key to Earth's terrestrial water, carbon, and water cycles. It also influences how and when the soil may freeze or thaw, a key component of understanding frozen ground and its extent.
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Analysis - Sea Ice Today
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Explore sea ice, ice sheet and snow conditions
Sea Ice Today
Read monthly analyses about polar weather and climate conditions, the state of sea ice, and ice sheet conditions in Greenland and Antarctica when warranted; also, explore near-real-time maps and graphs of Arctic and Antarctic sea ice extent.
Ice Sheets Today
Explore near-real-time melt maps and graphs of the Greenland Ice Sheet and periodic data images of the Antarctic ice sheet; plus read through a decade of scientific ice sheet condition analyses from 2015-2025.
Snow Today
Check out data images of snow conditions in near-real time across the western United States, Alaska, and western Canada, using a combination of satellite data and surface observations; read monthly snow condition analyses from January to June.
Analysis - Sea Ice Today
With the generous support of the Climate Science and Communication Fund from Surge Climate Talent, NSIDC’s Ice Sheets and Sea Ice News and Analysis (ISSINA) is able to start up monthly science assessments for the Sea Ice Today site.
Data, research & analysis updates
The CryoSat-2 Level-4 Sea Ice Elevation, Freeboard, and Thickness, Version 1 (RDEFT4), and CryoSat-2 Level-1B Waveforms, Sea Ice Elevation, and Surface Roughness, Version 1 (RDWES1B) data sets
The ICESat-2 L4 Monthly Gridded Sea Ice Thickness, Version 4 data set, available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC), has been updated. The
With the generous support of the Climate Science and Communication Fund from Surge Climate Talent, NSIDC’s Ice Sheets and Sea Ice News and Analysis (ISSINA) is able to start up monthly science assessments for the Sea Ice Today site.
The SMAP Standard and Near Real-Time data sets, available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC), experienced a geolocation issue from 14 May 2026
The DMSP SSM/I-SSMIS Daily Polar Gridded Brightness Temperatures, Version 6 data set, accessible through the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC), has
ICESat-2 Calibration/Validation LVIS L3A Sea Ice Freeboard, Version 1 is now available at the NASA National Snow and Ice Data Center Distributed Active Archive Center (NSIDC DAAC). This data set
Across the planet, snow and ice play a vital role in regulating Earth's climate and providing freshwater resources
What is the cryosphere?
This section is your introduction to the frozen parts of our planet. Learn where the cryosphere lies and how it influences life on our planet. Dive deeper into each feature below.
Arctic weather & climate
The Arctic is known as Earth's refrigerator. Land surrounds a cold ocean, which is covered by a thin layer of perennial sea ice and snow. How do these white surfaces affect weather and climate, both global and regional?
Frozen ground & permafrost
More than half of all the land in the Northern Hemisphere freezes and thaws every year, while a quarter of the land has an underground layer that stays frozen all year long. How has life learned to thrive in such a harsh environment?
Glaciers
Two categories of glaciers exist: ice sheets and alpine glaciers. Ice sheets cover vast areas of land in broad domes. Alpine glaciers, are smaller, and found not only at the poles, but in high mountain regions across the globe.
Ice sheets
During a series of Pleistocene Ice Ages, vast areas of our planet were covered by land. As the planet warmed, about 12,000 years ago, the ice sheets retreated to two major land areas, Greenland in the Northern Hemisphere and Antarctica in the
Ice shelves
This part of the cryosphere is an extension of land ice that spreads out over cold ocean waters. Since they are key in regulating glacial movement, they are an indirect, yet critical component to sea level rise.
Sea ice
When the surfaces of bodies of water reach their freezing point, layers of ice form. Sea ice is unique in that the water must be colder than fresh water to freeze. As such, the polar regions are cold enough to allow sea ice to form.
Snow
When most people think of the cold parts of Earth, they think of snow. Snow is much more important to the planet than simply for recreational purposes. Learn how it impacts wildlife, communities, and the global climate.
Ask a scientist
Visit this area to read common questions that have been asked of our scientists and staff. Feel free to suggest your own question.
Cryosphere glossary
Words matter and their meanings even more so. Search for a specific word or browse the many interesting words characteristic of the cryosphere.