Arctic News: Teleconnections: Atmospheric river carrying moisture to Antarctica

Sunday, September 13, 2026

Teleconnections: Atmospheric river carrying moisture to Antarctica

The finger on the image below points at an area over Antarctica where a temperature anomaly of about +30°C was recorded on September 13, 2026.

The mechanism causing this very high temperature anomaly on Antarctica is an atmospheric river carrying warm, moist air from the Tropics to Antarctica, on the way taking up water vapor evaporating from the Southern Ocean, as illustrated by the image below.

There are huge pressure differences between areas, facilitate this strong atmospheric river, as illustrated by the image on the right.

There are a number of causes behind these conditions.

Firstly, air temperatures in the Tropics are high. The image below, from an earlier post, shows surface air temperatures in the Tropics through September 4, 2026, when the temperature in the Tropics was 26.27°C or 79.29°F, an anomaly of 1.33°C or 2.39°F versus 1979-2000. The globe (inset bottom right) shows surface air temperature anomalies versus 1991-2020 on September 4, 2026 with the Tropics highlighted.

Secondly, sea surface temperatures are high. The image below shows that on September 12, 2026, the sea surface temperature was 21.05°C, an anomaly of 0.68°C versus 1991-2020.

[ -70°C near South Pole ]

The globe on the above image shows sea surface temperature anomalies on September 12, 2026, with high anomalies showing up on the Southern Hemisphere.

Thirdly, it is currently winter in the Southern Hemisphere, and the temperature can be -70°C or even lower near the South Pole and over East Antarctica, as illustrated by the image on the right, from the Antarctica page.

This currently large temperature difference between the Equator and the South Pole increases the strength of the Jet Stream in the Southern Hemisphere, enabling the Jet Stream to cross Antarctica.

The above image illustrates the large temperature difference between the Equator and the South Pole causing the Jet Stream to cross Antarctica. At the green circle, wind at 250 hPa is as fast as 259 km/h and Instantaneous Wind Power Density is 79 kW/m² on September 13, 2026.

The image on the right shows warm, moist air being carried in the form of an atmospheric river toward and over Antarctica on September 13, 2026.

The amount of snow falling on Antarctica can be significant. The image below, from the Antarctica page, shows a 3-hour precipitation accumulation of 16.9 kg/m² on August 25, 2026.

The image below shows that on September 12, 2026, a surface temperature of -0.3°C or 31.4°F was recorded near the coast of Antarctica (left), while a temperature of 5.2°C or 41.4°F was recorded over Antarctica at 1000 hPa.

The image on the right shows an area in the stratosphere (at 70 hPa or at about 17.5 km altitude) with a relative humidity of 100% (at the green circle) giving an idea of the strength at which water vapor is getting pushed into the air over Antarctica.

At a relative humidity of 100%, water vapor turns into solid ice crystals, since the temperature of the moist air in the stratosphere is very low (-91.0°C or -131.8°F at the green circle).

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 a result of the extra snowfall over Antarctica, the Southern Ocean surface is getting more salty. In salty water, sea ice can start melting when the temperature rises to about -2°C (28.4°F), while freshwater remains frozen as long as the temperature remains below 0°C (32°F).

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 this self-amplifying feedback loop.

An additional danger is that water vapor reaching the stratosphere can destroy the ozone layer. Atmospheric rivers carrying moisture to Antarctica are increasingly common events, as discussed at the Antarctica page.

Conclusion

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.

The ClimatePlan by Sam Carana calls for implementation of sets of feebates, with fees imposed on sales of polluting products and the revenues from those fees used to fund rebates on cleaner alternatives. Sets of feebates are best implemented ASAP, separately and preferably locally, with disputes handled by Local People's Courts where randomly-chosen local residents deliver verdicts on whether policies confirm the weight of best-available science. Where needed, Climate Emergency Declarations can support progress.

Links

• Climate Reanalyzer
https://climatereanalyzer.org

• Nullschool.net
https://earth.nullschool.net

• Copernicus
https://pulse.climate.copernicus.eu