March temperatures were up to 9 degrees Celsius

 "March temperatures were up to 9 degrees Celsius (16 degrees Fahrenheit) higher than average north of the Canadian Arctic Archipelago, up to 6 degrees Celsius (11 degrees Fahrenheit) above average in the East Siberian Sea, but up to 5 degrees Celsius (9 degrees Fahrenheit) above average over a wide area," they said.

This warmth took its toll. In March, the amount of sea ice across the Arctic is usually still growing, and typically reaches its winter maximum extent around the middle or in the latter half of the month. However, this year, the extent instead slowly declined during the month.

This graph of Arctic sea ice extent shows the peak of 2022 in relation to the past four years and 2011-2012, which was the precursor to the lowest summer sea ice extent on record so far. Credit: NSIDC

The maximum for winter sea ice extent in the Arctic was reached on Feb. 25. That is one of the earliest maximums since satellite tracking of sea ice began in 1979. The current record is held by 1989 and 1996, when the maximum occurred on Feb. 24.

While the winter maximum extent gives no indication of what's to come with the September minimum, sea ice across the Arctic is in very unhealthy shape. The amount resilient, multi-year ice has been declining for years.

The two panels of this image show the age of sea ice across the Arctic in the last week of March, both in 2000 and 2022. Lighter colours represent older ice. The amount of older, multi-year ice has decreased significantly over the past 22 years. Credit: NOAA Climate.gov/NSIDC

When satellite tracking of sea ice began, 43 years ago, the amount of sea ice that survived the northern hemisphere summer covered over half of the area of ​​the Arctic Ocean. This persistent ice, which is mostly located north of the Canadian Archipelago and Greenland, survived year by year, and it was much thicker and stronger than the young ice that formed and melted each year. However, as the maps shown above reveal, global warming has been causing the amount of multi-year ice to dwindle, while the area of ​​younger ice has increased dramatically.

This trend is strengthening a climate feedback loop in the Arctic. Younger sea ice is thinner and thus more vulnerable to being fractured and scattered by storms and wind patterns. More of the dark ocean surface is exposed as this ice breaks up, which allows the water to absorb more sunlight, and thus store more heat. The increase in heat then causes the loss of more multi-year ice, increasing the amount of younger ice, and so on. As this continues, we are getting closer and closer each year to seeing the Arctic Ocean completely ice-free by late summer.