Tuesday, May 10, 2022

As La Niña cooled the globe in March, the Arctic was running a high fever



The Weather Network

With the tally of global temperatures complete, last month ranked as the fifth hottest March of the past 143 years. Meanwhile, Arctic temperatures soared far above average.

Across the equatorial Pacific Ocean, the cooling influence of La Niña continues to dominate. As a result, global temperatures have been on the more moderate side so far in 2022, with each month ranking at least in the top 10 hottest in the record books.

March 2022 continued that trend, with the major climate agencies — NASA, NOAA, the Japanese Meteorological Agency, and Europe's Copernicus Climate Change Service — ranking it as the 5th warmest month of March since 1880.This graph ranks each global monthly average temperature against the average temperature for each month from 1980 to 2015, putting each into perspective for Earth’s seasonal cycles. March 2022 ranked as the fifth hottest month of March since 1880. Credit: NASA GISS

By comparison, the relative heat across the Arctic is remarkable.

According to NASA, the globe was, on average, just over 1°C warmer than average during the month of March. However, temperature anomalies across the Arctic Circle were among the highest seen across the entire planet, soaring to nearly 7°C warmer than normal for the month.

As La Niña cooled the globe in March, the Arctic was running a high feverHere, NASA's global temperature anomaly map for March 2022 (left) is combined with a graph (on the right) showing the average temperature anomaly based on latitude from the south pole (bottom of graph) to the north pole (top of graph). 
Credit: NASA GISS/Scott Sutherland

This 7°C temperature anomaly is the average computed across the entire Arctic. However, in their latest report, the US National Snow and Ice Data Center (NSIDC) breaks down a much more regional look at the temperature.

"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.


As La Niña cooled the globe in March, the Arctic was running a high fever
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.


© Provided by The Weather NetworkAs La Niña cooled the globe in March, the Arctic was running a high feverThe 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.

Scott Sutherland -
 Apr 27, 2022
 The Weather Network

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