The surface with floating ice in the Antarctic (or Southern) Ocean has been reduced in the first fortnight of this month of February to reach a new minimum since precise data on these circumpolar ice sheets are available. Specifically, the United States National Snow and Ice Data Center (NSIDC) has indicated that on Monday, February 13, the ocean surrounding Antarctica had an ice cover of 1.91 million cubic meters. square kilometres, the lowest figure in an official record that started in 1979.
The experts from this specialized center also recall that the summer season at the South Pole is still affecting floating ice and glaciers. In fact, the previous minimum corresponds to the 1.92 million km2 recorded on February 25, 2022. “It is likely that there are a couple more weeks left in the melt season, so the extent is expected to decrease further before reaching its annual minimum”, states the NSIDC in an official statement published on the 14th. In recent years, the annual minimum for floating ice in the Antarctic has occurred between February 18 and March 3.
The melting of (floating) sea ice has no direct impact on the feared global sea level rise because when the ice is floating on water and it melts, the total volume that the water plus ice occupied remains the same. However, it must be remembered that a part of the sea ice in this southern part of the planet surrounds the huge ice shelves of Antarctica and that if it melts the floating ice it is easier for the ice of the glaciers (which is now on the surface terrestrial) moves to the sea and melts, a phenomenon that does cause a rise in sea level, according to the NSID.
The upper map shows the areas surrounding Antarctica with floating ice on February 13, 2023. The softer blue areas indicate thin ice, which may disappear in the coming weeks. The orange limits mark the areas covered by ice in other years for these same dates (average from 1981 to 2010).
The Antarctic cycle undergoes significant annual variations, with melting ice during its summers and freezing in southern winters. Global warming is disrupting these cycles, with increasing ice losses. Antarctic sea ice extent as of February 13, 2023 is shown in the top graph, along with daily ice extent data for the previous four years and the record year. Winter 2022-2023 is shown in blue, 2021-2022 in green, 2020-2021 in orange, 2019-2020 in brown, 2018-2019 in magenta, and 2013-2014 in dashed brown. The median from 1981 to 2010 is in dark gray. The gray areas around the median line show the interquartile and interdecile ranges of the data, as specified by the NSIDC .
