The long-term pattern for sea ice within the south is flat, whereas the worldwide pattern factors downward.
In February 2022, sea ice round Antarctica reached the bottom extent ever noticed for the reason that begin of the satellite tv for pc document in 1979. It marks the primary time that the ice was noticed to shrink beneath 2 million sq. kilometers.
Sea ice in southern polar waters reached its lowest extent on February 25, 2022, at 1.92 million sq. kilometers (741,000 sq. miles). That’s 190,000 sq. kilometers (73,000 sq. miles) beneath the earlier record-low reached on March 3, 2017. Compared to the common minimal, the ocean ice this 12 months is lacking an space about twice the scale of California.
The map above reveals the ice extent on the day of its document low. Extent is outlined as the full space during which the ice focus is not less than 15 %. The yellow define reveals the median sea ice extent for February from 1981–2010. A median is the center worth: That is, half of the extents have been bigger than the yellow line and half have been smaller.
The 2021-2022 melting season started sooner than regular, after the ice reached its seasonal most extent on September 1, 2021, after which rapidly declined via the austral spring and summer season. According to Walt Meier, a sea ice researcher on the National Snow and Ice Data Center, winds have been the principle motive for the low ice situations this 12 months. He defined that the winds across the continent have been “much stronger than normal,” which rapidly pushed ice north into hotter waters the place it melted. An exception was within the Weddell Sea, the place winds pushed the ice edge south.
Now, one month after sea ice reached its annual minimal, Meier stated that the speed of development seems regular. Even the heatwave that despatched Antarctica’s air temperatures hovering within the third week of March doesn’t appear to have slowed the expansion. “It is really the ocean temperatures that count,” Meier stated, “and a brief heat wave won’t affect things too much in that regard.”
It stays to be seen how a lot ice will regrow this 12 months. While it’s common for Antarctic sea ice to soften almost all the way in which again to the shoreline throughout the austral summer season, the ice grows unconstrained via autumn and winter. After months of development (February to September), new sea ice usually spans an space of ocean about twice the scale of the continental United States.
From 12 months to 12 months, Antarctic sea ice will be extremely variable; since 2013 it has reached its highest excessive and its lowest low since document conserving started. A surge of sea ice development in 2014 and 2015 enhanced a small upward pattern within the long-term document. But over the previous seven years, sea ice has typically been at or beneath common, together with record-low minimums in 2017 and 2022. The long-term pattern now seems flat, and due to the variability, isn’t thought-about statistically vital.
In distinction, sea ice within the Arctic reveals a transparent downward pattern. That signifies that globally, the planet is dropping sea ice. “Overall, for the Arctic and Antarctic combined,” Meier stated, “the trend is definitely still downward.”
NASA Earth Observatory photographs by Joshua Stevens, utilizing knowledge from the National Snow and Ice Data Center.