Antarctic Sea Ice Bulletin February 2024

 

Key take-aways

  • Sea ice cover in the Antarctic has reached its annual minimum extent on the 20th of February, 20% below the long-term average (1993-2010).
  • Sea Ice volume is currently at 1.18 thousand km³, 47% lower the long-term average (1993-2010).
  • February 2024 remains another year of low sea ice extent and volume for the Antarctic.

Sea Ice Extent

Sea ice antarctic

Figure 1: The 1993-2024 Antarctic daily sea ice extent. Global 1/12° forecasting and reanalysis systems. Source: European Union, Copernicus Marine Service Data 2024 I © Mercator Ocean 
sea ice anomaly

Figure 2: The 1993-2024 Antarctic Sea ice extent daily anomaly (using 1993-2010 climatology). Global 1/12° forecasting and reanalysis systems. Source: European Union, Copernicus Marine Service Data 2024 I © Mercator Ocean 

Antarctic sea ice cover has reached its annual minimum extent of 1.86 million km² on the 20th  of February 2024.  This represents a loss of 0.49 million km² compared to the 1993-2010 long term average (2.36 million km²), or 20% less the same period. February 2024 shows another exceptional low extent (after the record-low in February 2023, since satellite record).


Sea Ice Concentration

On the 20th of February 2024, the Antarctic Sea ice concentration (figure 2 red line) was noticeably below the long-term average between 1993 and 2010 (figure 2 black line) for the same date in the year. Compared to the 1993-2010 period, large areas of sea ice cover are missing in the Atlantic and Pacific sectors (figure 1).

Figure 3: Antarctic Sea ice concentration (red) for 20th February 2024. The black line represents the 1993-2010 average (climatology) for the same date in the year. Global 1/12° forecasting (Lellouche, 2018) and reanalysis (Lellouche, 2022). Source: European Union, Copernicus Marine Service Data 2024 I © Mercator Ocean


Sea Ice Volume

Figure 4: The 1993-2024 Antarctic daily Sea ice volume. Global 1/12° forecasting and reanalysis systems. Source: European Union, Copernicus Marine Service Data 2024 I © Mercator Ocean 
Figure 5: The 1993-2024 Antarctic Sea ice volume daily anomaly (using 1993-2010 climatology). Global 1/12° forecasting and reanalysis systems. Source: European Union, Copernicus Marine Service Data 2024 I © Mercator Ocean  

The Antarctic sea ice volume has reached a volume of 1.18 thousand km³ on the 20th of February 2024.  This represents a loss of 1.05 thousand km³ compared to the 1993-2010 long term average (2.24 thousand km3), or the equivalent to a 47% loss in sea ice volume. In the last two years, minimum sea ice volume in the Antarctic was 50% below the 1993-2020 yearly minimum average. 


Antarctic Sea Ice Volume trend  

Antarctic Sea Ice Volume yearly minimum
Figure 6: Antarctic sea ice volume yearly minimums in the Southern Hemisphere for the 1993-2024 period. The white dashed line represents the long-term trend. Source: European Union, Copernicus Marine Service Data 2024 I © Mercator Ocean 

After nearly 30 years of a highly variable sea ice cover in the Antarctic region throughout the year, and therefore no clear trend, the last few years have shown a slight negative trend, particularly when considering the annual minimum value (measured in February). The 1993-2024 trend (figure 6) represents a loss of 0.25 thousand km³ per decade. 

Monitoring the sea ice cover in this period of the year is crucial because it represents the annual minimum sea ice coverage in the Antarctic. These measurements provide a vital indicator on the changes happening every year, as they serve as a reference for seasonal contrasts in sea ice cover. 

Definitions:
  • Sea ice extent – area covered by a significant amount of sea ice, at least 15% sea ice concentration (km²).  
  • Sea ice concentration – percentage of sea ice cover within the data grid cell. 
Notes:

This Mercator Ocean bulletin was developed by Clement Bricaud, Gilles Garric, Andreia Ferreira de Carvalho and Gratianne Quade. 

Products and data used:  GLORYS12V1 global ocean eddy-resolving (1/12° horizontal resolution, 50 vertical levels) reanalysis covering the altimetry (1993 onward). https://doi.org/10.48670/moi-00021 

The Operational Mercator global ocean analysis and forecast system at 1/12 degree. https://doi.org/10.48670/moi-00016 

References:

Lellouche, J.-M., Greiner, E., Bourdallé-Badie, R., Garric, G., Melet, A., Drévillon, M., Bricaud C., Hamon, M., Le Galloudec, O., Regnier, C., Candela, T., Testut, C.-E., Gasparin, F., Ruggiero, G., Benkiran, M., Drillet, Y., Le Traon, P.-Y. (2021) The Copernicus Global 1/12° Oceanic and Sea Ice GLORYS12 Reanalysis. Front. Earth Sci. 9:698876. doi: 10.3389/feart.2021.698876

Lellouche, J.-M., Greiner, E., Le Galloudec, O., Garric, G., Regnier, C., Drevillon, M., Benkiran, M., Testut, C.-E., Bourdalle-Badie, R., Gasparin, F., Hernandez, O., Levier, B., Drillet, Y., Remy, E., and Le Traon, P.-Y.: Recent updates to the Copernicus Marine Service global ocean monitoring and forecasting real-time 1∕12° high-resolution system, Ocean Sci., 14, 1093–1126, https://doi.org/10.5194/os-14-1093-2018, 2018.  

More on the topic:  

2023 was an unusual year for sea ice extent. What to expect from this season’s Arctic and Antarctic sea ice? – Mercator Ocean (mercator-ocean.eu) 

Antarctic Sea Ice Reaches Lows Never Before Observed – Mercator Ocean (mercator-ocean.eu) 

Antarctic Sea Ice Extent | CMEMS (copernicus.eu) 

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