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Arctic sea ice extent was 10.31 million km² on December 4, 2022. At this time of year, extent was smaller only in two years, i.e. in 2016 and 2020, both strong El Niño years. With the next El Niño, Arctic sea ice extent looks set to reach record lows.  The  NOAA image  on the right indicates that, while we're still in the depths of a persistent La Niña, the next El Niño looks set to strike soon. The image below shows high sea surface temperature anomalies near the Bering Strait on December 2, 2022, with a "hot blob" in the North Pacific Ocean where sea surface temperature anomalies are reaching as high as 7°C or 12.6°F from 1981-2011. The Jet Stream is stretched out vertically from pole to pole, enabling hot air to enter the Arctic from the Pacific Ocean and from the Atlantic Ocean. The image below shows a forecast for December 5, 2022, of 2m temperature anomalies versus 1979-2000, with anomalies over parts of the Arctic Ocean near the top end of the scale. On Dec...

The image on the right shows a NASA Worldview satellite image of a blue Beaufort Sea (with Barrow, Alaska, at the top left, on September 7, 2022).  The image shows that there is a lot of open water between the coast of Alaska and the sea ice. Such a satellite image provides a visual way to determine how much sea ice is present. It can be hard to determine where there is open water and where the sea ice starts; the sea ice is often covered by clouds; furthermore, even when there are no clouds, the question remains what is to be regarded as sea ice and what is to be regarded as water.  Another way to measure how much sea ice is there is to look at sea ice concentration. Sea ice concentration in the Central Arctic region has been very low for some time.  The image on the right, from an earlier post , shows that on August 12, 2022, sea ice concentration in a large area close to the North Pole was as low as 0%.  In the two images below, Nico Sun  calculates the ...

Arctic sea ice extent was 5.88 million km² on August 21, 2022, larger in extent than in any of the years from 2010 through 2021 at this time of year, as illustrated by the NSIDC image below.  At first glance, one might think that this relatively large extent was a sign of healthy sea ice. After all, the larger the sea ice, the more sunlight gets reflected back into space. At the same time, however, the situation is very dangerous, as there is a growing risk that large eruptions of methane will occur from the seafloor of the Arctic Ocean. Why is the situation so dangerous? There are many contributors to the danger, three of them are: 1. Ice acts as a seal Ice acts as a seal, insulating the soil from warmer air and holding the soil together, like a glue. A 2022 study by Elizabeth Webb et al. concludes that rainwater carries heat into the soil and accelerates permafrost thaw, and the glue that holds the soil together disappears. This can open up underground channels that drain the s...

Sea Ice Extent Arctic sea ice extent has fallen strongly in June 2022. On June 22, 2022, Arctic sea ice extent was among the lowest on record for the time of year, as illustrated by the above image, adapted from the National Snow and Ice Data Center ( NSIDC Chartic ).  The image below, from an animation by Zachary Labe, shows Arctic sea ice extent up to June 20, 2022, based on Vishop data . The yellow line is the year 2022. The white line shows extent for the year 2012, when it reached a record minimum in September. The blue line shows extent the year 2020, when the minimum in September was second lowest.   The image below, adapted from Vishop , shows that on June 23, 2022, global sea ice extent was at a record low for the time of year. La Niña [ adapted from NOAA - click on images to enlarge ] The fact that sea ice is so low for the time of the year is the more striking as we are currently in the depths of a persistent La Niña, which suppresses the temperature rise. El ...