Antarctic sea ice reaches a record low, a year after the previous one
Antarctic summer minimum extent falls below the previous record set in February 2022, which had itself been the first below two million square kilometres in the satellite era. The significance is that until about 2016 Antarctic sea ice had shown no decline at all, and in some years a slight increase - the two hemispheres had been behaving differently, and then the southern record turned sharply. Whether that is a regime shift or extreme variability in a short record is genuinely unresolved.
Observed — measured or witnessed, with the observation cited.
Subjects
- Sea Ice · natural phenomenon · Both polar oceans · not located
- Antarctica · region · Antarctic
- Southern Ocean · maritime region · Circumpolar, south of roughly 40°S · not located
Evidence
Partly verified — Core facts are sourced; some optional detail is deliberately absent.
Sea Ice Index
A continuous, consistently processed record of sea-ice extent in both hemispheres exists from 1979, from which the Arctic September minima of 2007 (approximately 4.2 million km2) and 2012 (approximately 3.4 million km2) and the Antarctic February minima of 2022 and 2023 (the first below 2 million km2 in the record, and lower again the following year) are drawn. V55 VERIFICATION BASIS: nsidc.org was probed during production and refused by the network egress proxy, and the WebSearch budget was exhausted. EVERY NUMERIC VALUE IN THIS RECORD IS APPROXIMATE AND UNCHECKED, given to one or two significant figures for that reason. A curator must replace them with values read from the Sea Ice Index before publication.
National Snow and Ice Data Center (NSIDC), University of Colorado Boulder · continuously updated; record begins 1979 · Partly verified
NSIDC Sea Ice Index, https://nsidc.org/data/seaice_index - daily and monthly Arctic and Antarctic sea-ice extent and concentration from passive-microwave satellite observations
Recorded on Sea Ice
- The factory ship Lancing takes a stern slipway south
- The Antarctic blue whale catch reaches its all-time peak
- The International Geophysical Year puts twelve nations on the ice at once
- The Antarctic Treaty is signed at Washington
- The continuous satellite sea-ice record begins
- CCAMLR is agreed at Canberra
- Vostok records minus 89.2 degrees Celsius
- The Southern Ocean Whale Sanctuary is adopted
- A long-term decline in krill density is linked to winter sea ice
- The Arctic summer minimum drops far below anything previously observed
- The lowest Arctic sea-ice extent in the satellite record
- Dedicated Antarctic Blue Whale Project voyages
- The Halley Bay emperor colony fails and does not recover
- CCAMLR adopts the Ross Sea marine protected area
- Baleen whale consumption is re-measured, and the krill paradox sharpens
- The emperor penguin is listed as threatened under the US Endangered Species Act
- The only published Antarctic blue whale satellite tracks are released as data
- Antarctic sea ice reaches a record low, a year after the previous one
- Antarctic meltwater is projected to slow the abyssal cell
- A physics-based early warning signal is proposed
Related
Related because they share a subject in the Atlas — never because the text looks similar.
- A physics-based early warning signal is proposed · 2024-02
- The Madrid Protocol becomes open to a review conference · 2048 (earliest possible review)
- The only published Antarctic blue whale satellite tracks are released as data · 2023
- Antarctic meltwater is projected to slow the abyssal cell · 2023
- The emperor penguin is listed as threatened under the US Endangered Species Act · 2022-10-25
- Baleen whale consumption is re-measured, and the krill paradox sharpens · 2021-11
- The Halley Bay emperor colony fails and does not recover · 2016 onward
- CCAMLR adopts the Ross Sea marine protected area · 2016-10