Arctic News: Antarctica

Antarctica

[ minus 70.2°C near South Pole ]

Strong Jet Stream

In winter in the Southern Hemisphere, temperatures lower than -70°C are recorded near the South Pole, as illustrated by the image on the right. At this time of year, the temperature difference between the Equator and the South Pole is large, strengthening the Jet Stream.

This is illustrated by the image below, dated July 25, 2026, 09:00 UTC. At a location marked by the green circle, wind at 250 hPa reaches a speed of 321 km/h, while Instantaneous Wind Power Density is 143.1 kW/m².

[ snowfall over Antarctica, forecast for August 2, 2026 ]

At times, the Jet Stream can move over parts of Antarctica, enabling warm, moist air to move from the Southern Ocean and reach Antarctica.

Warm, moist air can travel in the form of atmospheric rivers toward Antarctica, and this can result in snowfall over Antarctica, as illustrated by the forecast on the right.

It can also result in very high temperatures anomalies. The image below shows a forecast with areas over Antarctica reaching temperature anomalies of about +30°C on July 18, 2026, i.e. winter heatwave conditions in some areas in and around Antarctica, while other areas experience very low temperatures.

High temperatures anomalies

The image below also shows a forecast with some areas over Antarctica reaching temperature anomalies of about +30°C, this time on August 3, 2026.

The combination image below shows the Jet Stream moving over West Antarctica and atmospheric rivers of moisture moving toward Antarctica, coming with snowfall and relative humidity as high as 100% on Antarctica on August 1, 2026.

[ click on images to enlarge ]

The combination image below shows wind pushing warm, moist air over West Antarctica resulting in high temperature anomalies and snowfall. The image on the left shows surface temperatures as high as -6.1°C on August 2, 2026, while the image on the right shows temperatures at 1000 hPa as high as 1.3°C at the same time and location on August 2, 2026.

The nullschool.net image below shows the Jet Stream at 250 hPa and sea surface temperatures as high as 10°C or 17.9°F south of South Africa on August 4, 2026.

[ click on images to enlarge ]

Antarctic sea ice

[ Precipitable water anomalies over Antarctica ]

In the Southern Hemisphere, water evaporates from the Southern Ocean and part of the resulting precipitation falls on the Antarctic ice sheet, thickening the snow layer, as illustrated by the image on the right, from an earlier post and showing a forecast of high precipitable water anomalies over Antarctica on August 20, 2025.

As a result, the Southern Ocean surface is getting more salty. Saltier surface waters sink more readily, allowing heat from the deep to rise, which can melt Antarctic sea ice from below, even during winter, making it harder for ice to reform. This vertical circulation also draws up more salt from deeper layers, reinforcing the cycle, as discussed in earlier posts such as this one.

The dramatic decrease in sea ice around Antarctica looks set to continue long-term, as a feedback that is amplified by albedo loss, lower emissivity, loss of the sea ice's latent heat buffer, ocean current changes and salinity changes.

Methane danger

While the Antarctic methane danger has been described before, such as in this April 2013 post, the main focus of the Arctic-news blog has long been on the Arctic, in particular on the East Siberian Arctic Shelf (ESAS). However, research published in 2025 highlights the dire situation in Antarctica, justifying an additional wider focus on global developments, as discussed on facebook.

Conclusion

The image below shows annual maximum daily precipitation change with a temperature versus 1850-1900 rise of 1.5°C, 2°C, and 4°C, from the IPCC AR6.

The situation looks set to deteriorate further. More water vapor causes more warming, since water vapor is a potent greenhouse gas. As more snow falls over Antarctica, the sea surface of the Southern Ocean increases in salinity, which speeds up melting of sea ice. The extra water vapor and increased melting of sea ice can both strongly accelerate the temperature rise, while water vapor that reaches the stratosphere also causes damage to the ozone layer.

The situation is dire and unacceptably dangerous, and the precautionary principle necessitates the danger to be acknowledged, while facilitating rapid, comprehensive and effective action to reduce the damage and to improve the outlook, where needed in combination with a Climate Emergency Declaration, as described in posts such as in this 2022 post and this 2025 post, and as discussed in the Climate Plan group.