April saw big decline in Arctic sea ice cover

Iqaluit’s average temperature was 2.4 C higher than the 1981 to 2010 record

This map by Dalhousie University’s Patrick Duplessis shows how some parts of the Arctic experienced unusually warm temperatures in April, while other spots were colder than usual.

By Jane George

This past April, the circumpolar world saw the lowest Arctic sea ice extent, or coverage, ever recorded since record-keeping began 40 years ago.

Meanwhile, temperatures in many locations also were above average.

At the same time, there were still some cold spots, such as in western Nunavut, but overall the planet continued to sweat it out, says the National Oceanic and Atmospheric Administration in its latest monthly global climate report, released on May 20.

The average global temperature in April was 0.9 C above the 20th-century average, making it the second-hottest April in the 140-year record, surpassed only by April 2016, the report said.

Even so, April was generally colder than normal in eastern Canada and western Nunavut this year. For Kugluktuk, April was actually colder than March, by 1.7 C, for the first time on record, said Dalhousie University weather-watcher Patrick Duplessis.

Still, there were warm moments: the April 12 high of -1.4 C in Rankin Inlet set a new record high for that date, beating the previous high temperature of -2.8 C set in 2015, with 40 years of weather data on record.

In Iqaluit, the average temperature in April was 2.4 C higher than the 1981 to 2010 record, Duplessis found.

Over most of the Arctic Ocean, temperatures remained above average, up to 8 C above average over the East Greenland Sea, although temperatures were as much as 8 C below average over the High Arctic islands, according to an analysis by the National Snow and Ice Data Center based satellite data from NOAA and NASA.

Here you can see the precipitous decline of sea ice cover in the Arctic over the past 41 years. (Graph courtesy of the NSIDC)

April 2019 marked the 18th consecutive April during which Arctic sea ice extent was below average, the data centre found.

It was also the smallest Arctic sea ice extent for April in the 41-year record.

The satellite-image analysis showed that the annual rate of decline for April ice extent between 1979 and 2019 was 38,800 square kilometres, or 2.64 per cent per decade, when compared to the 1981 to 2010 average, the data centre said.

And nearly all of the oldest ice, four years old or more, which once made up about 30 per cent of the sea ice within the Arctic Ocean, is gone.

As of mid-April 2019, the older ice made up only 1.2 per cent of the ice cover.

However, the amount of three- to four-year-old ice increased slightly, jumping from 1.1 per cent in 2018 to 6.1 per cent this year, the data centre said.

“If that ice survives the summer melt season, it will somewhat replenish the 4+ year old category going into the 2019 to 2020 winter,” said the monthly analysis, which noted that “there has been little such replenishment in recent years.”

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(3) Comments:

  1. Posted by Jim MacDonald on

    After another brutal record-breaking cold winter across the Arctic, it wouldn’t be abnormal for Arctic sea ice to show a big decline in May, because sea ice coverage peaks in March.

    To visually see the sea ice extent, thickness, and sea ice temperatures. Nothing out of the ordinary.

    Freezing cold temperatures and lots of snow has hit across Europe this spring.  In the USA, many cities recorded their coldest May with or without large record-breaking dumps of snow. (Crop loss because of frost or land too wet to plant means higher food prices to come?)

     Greenland continues to increase snow coverage, and cool, helping 26 of 47 largest glaciers to thicken, be stable or grow,(Sentinel-2, Landsat and Aster satellites). 
    Waters of Disko Bay to Melville Bay have cooled 1-2c since 2015 (Willis_et_al.,2018). North Atlantic sea continues cooling.

  2. Posted by Russell Potter on

    The information here compares this April with Aprils past, not this may with this March. Cold weather in various parts of the globe, or some unusually heavy snow in Greenland, aren’t the point: climate change isn’t a matter of such isolated data points, but a trend over time, a trend in a very complex system that will always produced anomalies of one sort or another at either end of the change spectrum. And the “cooler” north Atlantic is not a contradiction of global warming but a confirmation of it: as the temperature differentials necessary for thermodynamic flow and exchange decrease, the work that can by done necessarily declines — with the result that the Gulf Stream’s warmth no longer reaches as far, or exchanges as much heat, as it once did. Global warming, curiously, could produce a long period of unusually cold weather in the British Isles.

    • Posted by James on

      Are you saying that if you select from a range of data you can make what your saying sound supported by that data?

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