Ice Sheets Today | National Snow and Ice Data Center
网页2024年8月14日 · Together, the Antarctic and Greenland Ice Sheets contain more than 99 percent of freshwater ice on Earth. If they both completely melted, they would raise sea level by an estimated 67.4 meters (223 feet). Long-term satellite data indicate that through most of the twentieth century, the ice sheets made very little contribution to sea level, and ...
Snow Today - National Snow and Ice Data Center
网页2024年6月5日 · Snow Today is a NASA-funded research project that examines where snow is present, where it has snowed recently, and how much water is in the snow, while also comparing between snow today, snow yesterday, snow last year, and snow over the last few decades. You can find the following resources on our …
Glacier Quick Facts - National Snow and Ice Data Center
网页A glacier is an accumulation of ice and snow that slowly flows over land. Alpine glaciers are frozen rivers of ice, slowly flowing under their own weight down mountainsides and into valleys. Ice sheets exist only on Greenland and Antarctica, and they spread out in broad domes in multiple directions. A group of people explore the Perito Moreno ...
Arctic Weather and Climate | National Snow and Ice Data Center
网页Near the ocean, a maritime climate prevails. In coastal Alaska, along with Iceland and Scandinavia, the winters are stormy and wet, with snow and rainfall reaching 60 centimeters (24 inches) to 125 centimeters (49 inches) each year. Summers in the coastal regions tend to be cool and cloudy; average temperatures hover around 10 °C (50 °F).
Sea Ice Today - National Snow and Ice Data Center
网页5 天之前 · Since 2007, the Arctic sea ice minimum has dropped below 5 million square kilometers (1.93 million square miles) every year, except in 2009, 2013, and 2014, when extent barely crossed the 5 million square kilometer mark. Such low extents would have been hard to imagine in the 1990s, when extent ...
Charctic Interactive Sea Ice Graph - National Snow and Ice Data …
网页Graph. What it shows: For both the Arctic and Antarctic, the graph compares sea ice extent (area of ocean with at least 15 percent sea ice concentration) between all years selected. Charctic shows sea ice growth and retreat throughout the calendar year. The default display shows the current year, the record-low year, and climatology.
Glaciers - National Snow and Ice Data Center
网页A glacier is an accumulation of ice and snow that slowly flows over land. At higher elevations, more snow typically falls than melts, adding to its mass. Eventually, the surplus of built-up ice begins to flow downhill. At lower elevations, there is usually a higher rate of melt or icebergs break off that removes ice mass.
Science of Snow - National Snow and Ice Data Center
网页Science. For snow to fall, moisture must be present in the atmosphere. Snowstorms also rely heavily on temperature, but not necessarily the temperature we feel on the ground. Snow forms when the atmospheric temperature is at or below freezing (0°C or 32°F). If the ground temperature is at or below freezing, the snow will reach the ground.
Science of Glaciers - National Snow and Ice Data Center
网页Glaciers move by internal deformation of the ice, and by sliding over the rocks and sediments at the base. The weight of overlying snow, firn, and ice, and the pressure exerted by upstream and downstream ice deforms glacier ice, in a phenomenon known as creep. A glacier may slide on a thin layer of water at its base.
Why Glaciers Matter - National Snow and Ice Data Center
网页Why they matter. Glaciers, slow-moving rivers of ice, have sculpted mountains and carved valleys throughout Earth's history. They continue to flow and shape the landscape in many places today. But glaciers affect much more than the landscape. Glacier melt delivers nutrients into lakes, rivers, and oceans. Those nutrients can drive blooms of ...