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.
In 2026, the Arctic winter sea-ice extent (annual maximum extent) reached the lowest value since satellite observations began in 1979, following the previous record low in March 2025. As part of the Arctic Challenge for Sustainability ...
Earth Sciences
May 4, 2026
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Polar bears are intensely curious animals. That curiosity often brings them into contact with people and can put both species at risk from one another.
Plants & Animals
May 1, 2026
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In 1902, British explorer Robert Falcon Scott spotted a large group of large black and white birds at Ross Island, Antarctica. This was among the many milestones of Scott's famous Discovery expedition: the first breeding ...
Plants & Animals
Apr 15, 2026
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A 93-strong international expedition team has been exploring the northwestern Weddell Sea in the Antarctic on board the Alfred Wegener Institute's icebreaker Polarstern since February 8, 2026. In this key region for global ...
Earth Sciences
Apr 8, 2026
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We are what we eat. And in the ocean, most life-forms source their food from phytoplankton. These microscopic, plant-like algae are the primary food source for krill, sea snails, some small fish, and jellyfish, which in turn ...
Environment
Mar 31, 2026
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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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303
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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209
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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17
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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