Sea ice concentration is a quantitative geophysical parameter describing the fraction of a given ocean surface area covered by sea ice, typically expressed as a percentage or a unitless value between 0 and 1. It is derived from satellite remote sensing (e.g., passive microwave, SAR, optical sensors) or in situ observations using algorithms that discriminate ice from open water based on radiometric or spectral signatures. Sea ice concentration is fundamental for characterizing polar climate systems, validating sea-ice and coupled climate models, estimating surface heat and momentum fluxes, and supporting operational navigation, data assimilation, and reanalysis of cryospheric conditions.
A new Stanford University study has helped solve a mystery about dramatic swings in sea ice extent around Antarctica.
Earth Sciences
Mar 28, 2026
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248
For the second consecutive year, winter sea ice in the Arctic reached a level that matches the lowest peak observed since satellite monitoring began in 1979. On March 15, Arctic sea ice extent reached 5.52 million square ...
Earth Sciences
Mar 26, 2026
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Arctic sea ice reached its lowest level ever recorded, statistically tying last year's record, a leading US climate observatory for this geopolitically significant region said on Thursday.
Environment
Mar 26, 2026
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14
In 2016, Antarctic sea ice, which had previously shown record expansion, shifted rapidly toward unusually low levels. This abrupt shift left scientists scratching their heads, wondering why it had vanished so quickly despite ...
As climate change reshapes Arctic food webs, ringed seals will swim into risky polar bear territory if the menu is varied enough. This is the central finding of a new study published in Ecology Letters. UBC researchers tracked ...
Plants & Animals
Mar 18, 2026
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58
Sea ice around Antarctica expanded for several decades until a dramatic decline in 2015. The reasons behind this are revealed by research led by the University of Gothenburg, which is published in Nature Climate Change.
Earth Sciences
Mar 18, 2026
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New research reveals that changes following the recent and dramatic decline in Antarctic sea ice could help a low-nutritional species prosper, with major ramifications for food webs and biogeochemical cycles. The findings ...
Earth Sciences
Mar 16, 2026
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Arctic sea ice is headed for one of its smallest winter peaks on record, an AFP review of U.S. data showed Wednesday, as climate change shrinks the region's frozen cover and heightens geopolitical tensions.
Environment
Mar 11, 2026
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179
Antarctic sea ice coverage has likely rebounded this year, coming closer to its annual summer average after four years of extreme lows, US scientists said Monday.
Environment
Mar 9, 2026
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The tall black-and-white residents of Antarctica, who waddle around its icy landscape, are in peril thanks to the rapidly warming global climate. Emperor penguins go through an annual transformation called catastrophic molting, ...
