Arctic sea ice has reached its minimum extent for 2022, tied with 2017 and 2018 as the 10th lowest on record, according to preliminary data from the US National Snow and Ice Data Center (NSIDC).
The last 16 years have seen the 16 lowest minimum Arctic sea ice extents in the satellite record, it adds.
Tracking near the 2010s decadal average, Arctic sea ice extent during the summer of 2022 has been “uneventful”, a scientist tells Carbon Brief.
The melt season has been marked by “cloudier weather, favorable winds and stormy conditions across the mid-Arctic Ocean”, which prevented rapid melting, he adds.
At Earth’s opposite pole, however, sea ice extent has hit record lows in recent months. According to the NSIDC, Antarctic sea ice extent was at “record or near-record low levels” for most of the growing season before seeing a “spurt in growth” in September.
Arctic sea ice extent reached its annual minimum extent of 4.67 square kilometers (km2) on September 18, according to the NSIDC. This is the 10th lowest minimum in a satellite record stretching back 43 years – along with 2017 and 2018.
The minimum is 1.55 m km2 less than the average minimum extent for 1981-2010 – equivalent to twice the size of Texas – the NSIDC notes.
The map below shows Arctic sea ice extent on September 18. The orange line shows the 1981-2010 average for that day.
“Compared to some recent extreme years, this summer was relatively uneventful in the Arctic,” says Dr. Zack Labe — a postdoctoral researcher working at the NOAA Geophysical Fluid Dynamics Laboratory and the Atmospheric and Oceanic Sciences Program at Princeton University — for Carbon Brief.
He says that while this year’s ranking “may not sound very impressive at first”, it is “important to note how much has changed in the Arctic over the last few decades”. For example, Labe highlights decades-long trends of decreasing Arctic sea ice thickness. He adds:
“Despite the year-to-year variability and no new records observed this year, the long-term trends are very clear in the Arctic. This can be linked to anthropogenic climate change.”
Professor Julienne Stroeve – Professor of Polar Observation and Modeling at University College London and Senior Scientist at NSIDC – also notes the long-term trend of declining sea ice.
She tells Carbon Brief that “overall, the Arctic was not much warmer than average this summer”, but adds that “the ice extent still fell below 5m km2, which never used to happen before 2007”.
Slow starts and hot spells
The Arctic melt season started from the sea ice maximum – the point at which Arctic sea ice covers its largest area at the end of winter. This happened on February 25 – the third earliest in the satellite record. At 14.88m km2, the extent was the 10th smallest maximum ever.
The NSIDC says the Arctic’s summer melt season began in “fits and starts.” Their scientists highlighted several “extremely warm events” in March, which saw above-average air temperatures. For example, on March 14, air temperatures northwest of Greenland were up to 15C above average, they note, adding that these warm events were “associated with large transports of water vapor into the region”.
Wow – well above average temperatures were observed almost all over #Arctic Circle in March 2022… 😵💫
— Zack Labe (@ZLabe) 7 April 2022
However, the month saw a “very slow” rate of sea ice loss overall. By the end of March, the sea ice was 14.5 m km2, showing little change from the end of February.
The slower than average decline in ice cover continued into April. The average Arctic sea ice extent for April 2022 was 14.06 m km2 – the 11th lowest in the 44-year satellite record.
The NSIDC explains that strong offshore winds during the early summer season over Alaska’s northwest coast created polynyas – areas of open water surrounded by sea ice. After the first round of strong winds in late March, the polynyas “quickly refrozen”.
On April 12, further strong winds caused another polynya. The refreezing of this polynya was “noticeably slower” – caused by higher surface air temperatures at the end of the month, according to the NSIDC. Temperatures in most areas of the Arctic in April were 2 to 3C above average, it adds.
Labe tells Carbon Brief that the “cloudier weather, favorable winds and stormy conditions across the central Arctic Ocean” helped “prevent some of the melting and sea ice contraction that might otherwise have contributed to even lower arctic sea ice”.
In May, “only” 1.28m km2 of sea ice extent was lost, NSIDC says, with ice cover “above levels not seen since 2013”. Scientists at NSIDC attributed the extensive ice cover to lower-than-average temperatures in Baffin Bay, Canada.
Fluctuating air temperatures in the Arctic region continued into June. In Canada’s Hudson Bay, temperatures were 4 to 5C above average – leading to “unusually early” sea ice loss and “near record low” sea ice extent in the region. Meanwhile, temperatures over northern Greenland, northern Yukon and the North Slope, and easternmost Siberia were 2 to 4 C below average.
Overall, the average Arctic sea ice extent in June was the 10th lowest ever at 10.86 m km2.
Average June 2022 #Arctic Sea ice extent was the 10th lowest ever recorded
— Zack Labe (@ZLabe) 2 July 2022
While this melt season wasn’t record-breaking, Labe tells Carbon Brief there were still “notable anomalies” in the Arctic this summer.
For example, he notes that the Barents Sea region was “effectively ice-free” in early July. This was driven by “unusually early decline in Barents sea ice [leading] until more incoming solar radiation is absorbed in the open water”, he says. This “led to more ocean warming and subsequent sea surface temperatures were at least 4C above average”.
The average rate of Arctic sea ice decline from July to August continued at a “near average pace,” NSIDC says. While sea ice extent recorded on August 1 was “well below” the 1981 to 2010 average, it was the highest level since 2014 at 6.99 m km2.
NSIDC researchers called the amount of open water along the Eurasian coast of the Laptev Sea “remarkable”, but added that the pattern is “much less extreme than observed in 2020 and 2021”.
During the first half of August, air temperatures were “modestly above average from the Beaufort Sea over the Pole and towards the Kara and Barents Seas”, while they were “slightly below average” over parts of the East Siberian, Laptev and Bering Seas, according to the NSIDC.
As September arrived and the sun began to set on the Arctic melt season, sea ice extent tracked close to levels observed in 2010, NSIDC says. It adds that by mid-September the high-latitude polynes were frozen.
Low records in Antarctica
At Earth’s South Pole, sea ice extent has tracked record high or near record low levels for most of the year.
In February, Antarctica recorded a record low minimum sea ice cover, falling below 2m km2 for the first time in the satellite record.
In March, the continent experienced “unusual warmth” – with a high-elevation station in Russia recording temperatures more than 35C above average for the season. During this month, the Conger Ice Shelf in East Antarctica broke up into several large pieces. However, researchers at NSIDC say the event was not “directly related to the recent record low sea ice extent or the recent heat wave”.
Low sea ice extent levels continued throughout the Antarctic winter. In May, strong winds in the Bellingshausen and Amundsen seas brought warm conditions to the edge of the sea ice and led to a “slowdown” in ice growth.
A new record low ice extent was set on 20 June and air temperatures were above average across the continent throughout the month. In mid-July, Antarctic sea ice extent was 14.8 m km2 below the previous record daily low of 2017.
— Zack Labe (@ZLabe) 27 July 2022
Antarctic sea ice extent remained “at record or near record low extent” in August, according to the NSIDC. But as the Arctic Minimum approached, Antarctica experienced a “growth spurt”, it said.
On September 20, the NSIDC announced that “the extent has reached the 10th percentile [bottom 10%] for this time of year, still well below average, but no longer near the record low maximum”.
The map below shows the Antarctic sea ice extent on September 19. The orange line shows the 1981-2010 average for that day.
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