Ice in the Arctic Sea grows and shrinks between a minimum and maximum point as the changing seasons cause temperatures to fluctuate. The change in ice cover is tracked by US space agency NASA in collaboration with the National Snow and Ice Data Centre (NSIDC). This year, ice in the Arctic appears to have already peaked at its maximum with some of the lowest ice levels on record. According to NASA, the 2019 winter maximum has tied a 2007 record for the smallest amount of Arctic ice recorded by satellites.
The ice extent is not the lowest in history but has peaked below the 1981 to 2010 average maximum.
NASA said this year’s maximum reached an area of 5.71 million square miles or 14.78 million square km.
And at 332,000 square miles (860,000 square km) below the 1981 to 2010 average, the Arctic is now missing an area of ice the size of Texas.
NASA said: “The Arctic sea ice cover, an expanse of frozen seawater floating on top of the Arctic Ocean and surrounding seas, thickens and expands during the fall and winter months.
“The sea ice hits its maximum yearly extent sometime between late February and early April.
“It thins and shrinks during the spring and summer until it reaches its annual minimum extent in September.”
Outside of the natural icy cycle, NASA said the Arctic’s ice extent has been rapidly plummeting during both growth and melt seasons over the last 40 years.
The 2019 ice extent broke a dire string of record-low measurements since 2015 but the space agency said this is not necessarily a sign of recovery.
Melinda Webster, a sea ice scientist at NASA’s Goddard Space Flight Center, said: While this year wasn’t a record low, the maximum extent still points to there being a sustained decline in winter sea ice.
“The temperatures in the Arctic were a bit higher than average and we saw a lot of ice loss in the Bering Sea, but nothing this winter was as extreme or dramatic compared to recent years and the record lows.”
However, the NSIDC noted the ice extent figures are only preliminary at this stage and could still push the maximum higher.
The NSIDC expects to publish its final conclusions and full analysis of the ice later in April.
The agency will also examine some of the possible causes behind this year’s ice growth.
One possible cause, NASA argued, is the rise in Arctic water temperatures over the past decades.
As water temperatures spike, the sea’s ice pack has thinned and damaged the older and much thicker ice, which has protected the rest of the ice cover form melting.
Ron Kwok, a sea ice researcher with NASA’s Jet Propulsion Laboratory, said: “The large changes in ice coverage associated with the loss of the multiyear ice pack have already occurred.
“The seasonal ice now represents a larger fraction of the Arctic sea ice cover.
“Because this young ice is thinner and grows faster in the winter, it is more responsive to weather and makes the sea ice cover respond differently than before.
“It’s not that we won’t see new wintertime or summertime record lows in the next years – it’s just that the variability is going to be higher.”