Ocean circulation changes in the Southern Oceanįigure 6b. This is 100,000 square kilometers (38,600 square miles) more than the record low extent for March set in 2017. The March 2023 average sea ice extent around Antarctica was 2.80 million square kilometers (1.08 million square miles), the second lowest March on record. Despite regrowth, the Weddell Sea ice cover is well below its typical extent for the end of March. However, large areas of the coast, such as the southern Bellingshausen Sea coastline were still ice free other areas of open water persisted along the boundary between the Amundsen and Ross Seas. At the end of the month, the Ross Sea and Amundsen Sea were covered again with ice, and significant expansion of ice had begun in the Weddell Sea. About the dataĪntarctic sea ice extent expanded at a near-average pace in March following its record low extent on February 21. The magenta line shows the 1981 to 2010 average extent for that month. Antarctic sea ice extent for March 2023 was 2.80 million square kilometers (1.08 million square miles). These results are consistent with a new study that evaluated the thickness of ice from moorings in Fram Strait, finding a shift in the ice thickness after 2007 and a decline of the average residence time of ice in the Arctic Ocean. Since 2011, the older-than-four-year-old ice has comprised less than 5.5 percent of the Arctic Ocean. This is the same percentage as last year and contrasts starkly with the late 1980s when 30 to 35 percent of the Arctic Ocean’s ice was older than 4 years. Overall, there is almost no ice over four years old remaining-it now comprises just 3 percent of the total ice cover. The multiyear ice coverage has been variable since then, with no significant trend. This is much less than in the late 1980s when multiyear ice covered 60 to 65 percent of the Arctic Ocean.Ī rapid decline in multiyear ice coverage occurred after the then record 2007 September sea ice extent minimum. Multiyear ice covered 33.9 percent of the Arctic Ocean domain in the week of February 26 through March 4, 2023, slightly less than the 34.3 percent during the same week in 2022. As in recent years, there is far less multiyear ice (ice that has survived at least one summer melt season) and the oldest ice (ice that has survived several or more melt seasons) is nearly gone. Data and images from NSIDC EASE-Grid Sea Ice Age, Version 4 (Tschudi et al., 2019a) and Quicklook Arctic Weekly EASE-Grid Sea Ice Age, Version 1Īn important indicator of sea ice conditions is the sea ice age. The bottom graph is a timeseries of the percent of the sea ice extent within the Arctic Ocean domain (inset map) for the week of February 26 to March 4, 1985, through 2023 color categories are the same as in the maps. The top maps show sea ice age for the week of February 26 to March 4 for (a) 1985 and (b) 2023. Overall, extent decreased 170,000 square kilometers (65,600 square miles) during March 2023, compared to the 1981 to 2010 average March decrease of 220,000 square kilometers (84,900 square miles). Sea ice concentration within the ice pack was generally quite high in all areas, with the exception of the Sea of Okhotsk and the northern Barents Sea where the ice pack was more open. Lawrence, with smaller retreats in the Barents and Bering Seas. Ice extent was slightly below average in almost all areas, but particularly in the Sea of Okhotsk and in the Gulf of St. March monthly average extent was 990,000 square kilometers (382,000 square miles) below the 1981 to 2010 average of 15.43 million square kilometers (5.96 million square miles), but 150,000 square kilometers (57,900 square miles) above the record low set in March 2017 (Figure 1b).Īfter the March 6 seasonal maximum, extent declined for a week, but then remained almost constant during the second half of the month. The March 2023 average Arctic sea ice extent was 14.44 million square kilometers (5.58 million square miles), the sixth lowest March in the satellite record (Figure 1a). Sea Ice Index data.Ĭredit: National Snow and Ice Data Center The gray areas around the median line show the interquartile and interdecile ranges of the data. The graph above shows Arctic sea ice extent as of April 4, 2023, along with daily ice extent data for four previous years and the record low year.
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