Icycle on thin ice level 197/10/2023 ![]() As a result, Antarctic sea ice is relatively thin, often 1 meter (about 3 feet) or less. Because so little Antarctic ice persists through the summer, the majority of Antarctica’s sea ice is only one winter old. On average, about 40 percent of the Arctic Ocean’s winter ice cover remains at the summer minimum, whereas in the Southern Ocean only about 15 percent does. Map by NOAA, based on satellite data provided by the National Snow and Ice Data Center.īecause a substantial amount of Antarctic sea ice forms at lower, warmer latitudes, less ice survives the summer. Compared to median conditions from 1981–2010 (yellow line), the most recent minimum was the lowest on record throughout the month. This barrier means that sea ice can't form over the very coldest parts of the Southern Hemisphere.Īverage Antarctic sea ice concentration in February 2023, the month when sea ice reaches its summer minimum extent. Sea ice can expand freely across the Southern Ocean in winter, but it can get no closer to the South Pole than the Antarctic coastline will allow. The Antarctic is a continent surrounded by a vast ocean. Sea ice is always present over the North Pole and central Arctic, and it expands southward every autumn, but its expansion is checked by Eurasia, North America, and Greenland. The Arctic is an ocean basin largely surrounded by land. ![]() The differences in seasonal extremes are largely due to basic geography. Map by NOAA, based on satellite data provided by the National Snow and Ice Data Center. Maximum extent in 2022 was below the 1981–2010 median extent (yellow line) around most of the Antarctic continent, but within the innermost 80 percent of observed 1981–2010 extents. However, because of the extreme natural variability in Antarctic summer extent, the long-term trend is not statistically significant, and it’s too soon to tell whether the recent low extents mark the beginning of a significant decline.Īntarctic sea ice concentration in September 2022, the month of the maximum winter extent in the Southern Hemisphere. The past 8 years have brought below-average summer minimums-the longest such streak in the satellite record.The 2023 record-low extent was 1.05 million square kilometers (405,000 square miles) below the 1981–2010 average, and 136,000 square kilometers (52,500 square miles) below the previous record low reached on February 25, 2022.The 2023 summer minimum, a record low of 1.79 million square kilometers (691,000 square miles), occurred on February 21, 2023.The 2022 winter maximum was below the 1981–2010 average, but within the inner 80 percent of 1981–2010 observed extents.The 2022 winter maximum extent, 18.19 million square kilometers (7.02 million square miles), occurred on September 16, 2022.The overall long-term trend (since 1979) is nearly flat. In the past decade there have been record and near-record high extents, as well as record and near-record lows. More so than the Arctic, Antarctic sea ice extents are extremely variable, both seasonally and from year to year.
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