Arctic Sea Ice Reaches Second-Lowest Minimum on Record

Arctic Sea Ice Concentration, September 15, 2020.

Arctic sea ice likely reached its annual minimum extent on September 15, 2020, according to researchers at NASA and the National Snow and Ice Data Center (NSIDC).

Analyses of satellite data showed that the Arctic ice cap shrank to 3.74 million square kilometers (1.44 million square miles), making it the second-lowest minimum on record. Experts cautioned that the announcement is preliminary, and there is still a possibility that changing winds or late season melting could push the ice extent lower.

The map at the top of this page shows the sea ice extent—defined as the total area in which the ice concentration is at least 15 percent—at its 2020 minimum on September 15. The ice extent (white) on that day was far lower than the 1981-2010 average extent for the same day (yellow line). 2020 and 2012 remain the only years when sea ice extent has fallen below 4.0 million square kilometers (1.54 million square miles).

“The minimum this year is the unsurprising result of a continued long-term decline in Arctic sea ice,” said Alek Petty, a sea ice scientist NASA’s Goddard Space Flight Center. The lowest 14 ice extents on record have all occurred in the past 14 years.

Arctic Daily Sea Ice Extent Chart, September 15, 2020.

Numerous factors combined to shrink sea ice so much in 2020. In spring, a heatwave across Siberia set the stage for rapid early season melting. Also, sea ice was already much thinner going into the 2020 melt season than in years past—the accumulated result of the general long-term decline in summer sea ice extent. And scientists think warm water could be working its way under the ice and melting it from below.

Weather can also affect the amount of ice across the Arctic. From late July into early August, scientists watched an atmospheric low-pressure system spin over the Arctic Ocean and wondered how it would affect the ice. A similar storm in 2012 was a major cause of the lowest sea ice minimum on record. “The summer 2020 storm definitely had an effect, but it didn’t seem sufficient to cause the really significant loss of ice to drive a new record low,” Petty said.

In any given year, there are regional variations in air temperatures, water temperatures, and weather that promote or inhibit melting in different parts of the Arctic. By the date of the 2020 minimum, there was still more sea ice remaining in the Beaufort Sea compared to 2012, and slightly less in the Laptev and East Greenland seas.

NASA Earth Observatory images by Joshua Stevens, using data from the National Snow and Ice Data Center. Story by Kathryn Hansen, and includes reporting by Kate Ramsayer.

ArcticClimate ChangeEarth ObservatoryGlobal WarmingNASA
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  • Richie

    What a milestone! Or millstone. Consider the context, which the Goddard Institute apparently does not. Why use 1981-2010 as the baseline? Because there is no hard data before the satellite era. But the climate has been consistently warming since 1981, so of course sea ice is diminishing. (Prior to that, Hansen et al. expected a catastrophic new Ice Age.)

    Can any valid conclusions be drawn from such a short baseline period?

    For context, what was the ice extent at the peak of the Eemian interglacial? During how many of the past 5 million years has there been any ice in the Arctic? Closer to now, what was the proximate cause of the early 1920s Arctic warming that caused scientists to declare it might be transitioning to a “temperate zone”?

    I suggest that there is an element of disingenuousness in the phrase “second lowest on record.”

  • Nita Wingnut

    I see nothing disingenuous about clearly defining 1981 to 2010 as a baseline, then, according to actual satellite records, this really is the second lowest Arctic sea ice minimum.
    How else can they record this? They need to use actual recognized data.

    I see a fantastic maximum happening now in the Antarctica for 2020.
    There is a reminder of the colder conditions there in 2013 & 2014. After the horrible Antarctica heatwave of 2016, that ice pack is showing some real improvement.

  • Mike

    disingenuous!? i dont think anyone is holding back information here. Unless there have been new developments, the oldest ice core samples are 2.7 mil years old.. but, NONE of this matters ANYMORE! Theres no reversing what we have done and continue to do EVERY SINGLE DAY. All of the worlds ice that has been here for MILLIONS of years will soon be unprecidentingly gone! Do you think the US, india or russia could even slow down its global warming activities? I 100 percent dont believe they could. And China, being the mass producer of damn near everything, couldnt stop their global warming behaviour even if they wanted to they are so established and are going to be the worlds 1# super power if theyre not already. now, there are people trying to come up with a fix for the problem. Suggesting covering all of the remaining ice with mico glass beads!? Like thats going to work without causing a new global disaster.. look, this is a run away green house gas freight train and were all on it. This wont render the human race extinct at least for a while. But its gonna be getting a lot warmer, higher sea levels, and lots of death. I suggest you, try enjoy every single day you get even if most days suck.