15/04/2022

Record-low Antarctic Sea Ice in February 2022

Antarctic sea ice reached new record-low in February 2022.

A minimum Antarctic sea-ice extent for 2022 was reached on February 18 with an ice coverage of 2.17 million km², making this a new all-time record-low sea-ice extent since the start of the satellite observations. It is more than 3% lower than the previous record-low in 2017 (2.24 mill km²).
Despite this overall minimum the situation is quite diverse in the Antarctic. Let's have look at the challenges of monitoring sea-ice extent around this continent.
The table shows the top 5 lowest and 5 highest minima of sea-ice extent recorded in the Antarctic

After having reached some of the highest values in July and August 2021, the Antarctic sea-ice extent has been tracking low values after November. Beginning of 2022, the extent continued being low, and since mid-February, the extent dropped below the lowest daily extent values. The table shows the top 5 lowest and 5 highest minima of sea-ice extent recorded in the Antarctic, and at what day they occurred.
Despite the new significant record-low of the Antarctic sea ice it is still difficult to conclude anything about its long-term- and future trend. Before 2015, the Antarctic sea ice exhibited a slightly increasing trend over decades and reached record-high coverage in 2014 (or 2015 depending on the months considered). Thereafter, an abrupt change led to record-low values in 2017 and hereby resulted in some of the largest inter-annual variability observed in the sea-ice cover. Large inter-annual variabilities have continued since then and no clear trend has been observed.

In terms of monthly averaged values, February 2022 becomes the second-lowest on record, after 2017. The long-term trend for February is for the first time slightly negative (not statistically significant), see figure below. The daily sea-ice extent values from the previous and current year (black), plus the reference curves for 2014 and 2017, which were the two years with the highest and lowest ice extents ever recorded with satellite monitoring in the Antarctic. Note, that the present year 2022 combines a black and a red line which represents the slightly different retrieval methods behind the data. The black covers the Interim Climate Data Record data, and the red is the supplementing near-real-time data.
- The daily sea-ice extent values from the previous and current year (black), plus the reference curves for 2014 and 2017, which were the two years with the highest and lowest ice extents ever recorded with satellite monitoring in the Antarctic. Note, that the present year 2022 combines a black and a red line which represents the slightly different retrieval methods behind the data. The black covers the Interim Climate Data Record data, and the red is the supplementing near-real-time data.
Antarctic sea ice reaches new record-low in February 2022.
- Antarctic Sea Ice Extent reaches a new record low in February 2022
Influence of different oceans on regional sea ice extent
The Antarctic sea ice covers vast ocean areas.

The Antarctic sea ice covers vast ocean areas, and the sea ice in different regions may behave independently from each other. Thus, a record-low Antarctic sea-ice extent does not need to be applicable for the individual regional ice extents. Below, is shown the map of February 2022 sea-ice concentration and its anomaly from the climate reference period 1981-2010. The larger loss of sea ice in 2022 is seen to be concentrated in especially the Ross Sea, toward the Amundsen Sea, and in the outer part of the Weddell sea ice cover.

Below, the Antarctic monthly sea-ice condition for February 2022. [Left] February sea-ice concentration. [Right] Sea-ice concentration anomaly for February 2022 relative to 1981-2010. The sector between red lines is the Weddell Sea, between blue and red lines is the Bellingshausen and Amundsen seas, and between green and blue lines is the Ross Sea.
- The Antarctic monthly sea-ice condition for February 2022. [Left] February sea-ice concentration. [Right] Sea-ice concentration anomaly for February 2022 relative to 1981-2010. The sector between red lines is the Weddell Sea, between blue and red lines is the Bellingshausen and Amundsen seas, and between green and blue lines is the Ross Sea.
The daily sea-ice extent is computed for five sectors ; the Weddell Sea, Bellingshausen and Amundsen seas, the Ross Sea, Western Pacific and Indian sector. The ice extent indices are shown below together with the total Antarctic sea-ice extent.

Daily sea-ice extent values from the current year (black), and all available years since 1979. As on previous sea ice extent figure : the daily sea-ice extent values from the previous and current year (black), plus the reference curves for 2014 and 2017, which were the two years with the highest and lowest ice extents ever recorded with satellite monitoring in the Antarctic. Note, that the present year 2022 combines a black and a red line which represents the slightly different retrieval methods behind the data. The black covers the Interim Climate Data Record data, and the red is the supplementing near-real-time data.
- Daily sea-ice extent values from the current year (black), and all available years since 1979. The line colour represents the individual year. The colours are selected so that the years are grouped into decades. [Upper-left] Weddell Sea, [upper-right] entire Antarctic ocean, [lower-left] Bellingshausen and Amundsen seas, and [lower-right] Ross Sea. See the location of regional seas
Extreme events in the Antarctic

In addition to the record-low sea ice extent in February, a series of extreme events have been recorded in the Southern Hemisphere this season :
- Heat anomalies and record temperatures in East-Antarctic ;
- Ice shelf collapse in East-Antarctic ;
- Low number of birds in the Wedell Sea area.
Heat anomalies in East-Antarctic:

Several research communities and scientists have monitored the heat anomaly. More information can be found in this article from the Washington Post.
Low number of birds

The Norwegian Polar Institute reports that no birds were found in Queen Maud Land when they went for counting them. In 1984, there was 400.000 Antarctic Petrel (type of bird), in 2020 there was less than 100.000. This year there was almost none. Norwegian Polar Institute Story (In Norwegian).
Ice shelf collapse in East-Antarctic

This article documents the concerns of the scientific community. An ice shelf about the size of Rome has completely collapsed in East Antarctica within days of record high temperatures, according to satellite data.
Conclusion

Overall, Antarctic sea-ice extent reached a new record-low this February. Monitoring the individual regions however shows that there are strong local differences. Additional recorded extreme events are worrying the scientific community. Yet, the inter-annual variability in Antarctica is known to be quite strong. The different climatic signals are closely monitored to improve our knowledge over the continent. It is very challenging to draw conclusion from individual events as the situation might be very different when looking at regional areas.

Another viewing angle on the Antarctic sea ice will be allowed with a new OSI SAF Sea-Ice Type product over the Southern Hemisphere. It adds a new perspective to monitoring sea ice development in the Antarctic. Quicklooks of this new product can be found here and it was previously presented in this OSI SAF story. In the coming years we look forward to present sea-ice type trends around the Antarctic.
Further information

This story is based on content originally published on Cryo Met a website maintained by OSI SAF colleagues from the Norwegian Meteorological Institute - MET Norway : Signe Aaboe and Thomas Lavergne.

You can find continuous OSI SAF information about sea ice status at both poles on the following websites :
- OSI SAF High Latitude processing center
- Cryo MET Norway