Arctic News: November 2024

Tuesday, November 5, 2024

Sea ice alert

Sea ice

The image shows Arctic sea ice extent from October 14 to November 11, a period during which Arctic sea ice extent growth was slow in 2016, 2019 and 2020. The red line shows 2024 extent through November 5, 2024, when growth in Arctic sea ice extent was slow too, which is worrying, since El Niño conditions were prominent in 2016 and 2019, whereas La Niña conditions were prominent in October 2024 through November 5, 2024. Higher than usual temperatures during El Niño years typically slow down Arctic sea ice extent growth at this time of year. It is worrying for slow growth to occur during La Niña conditions in 2024.

The image below shows Antarctic sea ice extent during the months September and October, highlighting extent in 2023 and 2024, as compared to extent averages in previous decades.

As illustrated by the above image, Antarctic sea ice extent in September and October 2023 & 2024 was much lower than in previous decades, a huge difference that occurred during a period when little or no sunlight was reaching Antarctic sea ice. On November 9, 2024, Antarctic sea ice extent was 14.99 million km², a record low for the time of year.

Global sea ice typically reaches its annual maximum extent around this time of year, as Arctic sea ice expands in extent. On November 9, 2024, global sea ice extent was 23.34 million km², a record low for the time of year and well below the 24.15 million km² on November 9, 2023.

Higher ocean heat in combination with higher air temperatures over the Arctic Ocean are two drivers behind the slow growth in Arctic sea ice extent.

More than 1.5°C above 1903-1924 for 16 consecutive months

The above image, created with NASA data through October 2024 while using a 1903-1924 custom base, illustrates that the monthly temperature anomaly has been more than 1.5°C above this base for 16 consecutive months. The red line shows a trend (2-year Lowess Smoothing) associated with recent data and the trend indicates that the anomaly is rising.

[ click on images to enlarge ]

The map on the right with October 2024 temperature anomalies from 1951-1980 based on NCEP data shows high polar anomalies.

Similarly, the map below with October 2024 temperature anomalies from 1951-1980 based on ERA5 data shows high polar anomalies.

The 1951-1980 base for the maps is NASA's default base, but neither 1951-1980 nor the above 1903-1924 is pre-industrial. When using a pre-industrial base, anomalies are higher.

Jet Stream distortion

As a result of the narrowing temperature difference between the Arctic and the Tropics, the Jet Stream gets distorted. The image below shows a distorted Jet Stream (250 hPa) over the North Atlantic on November 11, 2024.

Precipitation

The image below shows an atmospheric river stretched out over the North Atlantic from the Tropics to the Arctic with high rainfall over the North Atlantic and snowfall over Greenland on November 11, 2024.

Water vapor

The image below shows a forecast for November 12, 2024, with precipitable water anomalies at the high end of the scale over the Arctic Ocean.

Feedbacks

The image below illustrates how multiple feedbacks can interact and jointly contribute to further acceleration of the temperature rise.

[ from earlier post ]

There are many feedbacks and other mechanisms active and they are interacting on top of driving up temperatures individually.

Albedo change is a feedback that can have a huge impact. The currently very low global sea ice extent is a self-reinforcing feedback, as it results in less sunlight getting reflected back into space and more heat getting absorbed by oceans.

Extra water vapor is another self-reinfocing feedback, since water vapor is a potent greenhouse gas.

These are just some of the feedbacks that can contribute to further acceleration of the temperature rise, as discussed in an earlier post.

Climate Emergency Declaration

The situation is dire and the precautionary principle calls for rapid, comprehensive and effective action to reduce the damage and to improve the situation, as described in this 2022 post, where needed in combination with a Climate Emergency Declaration, as discussed at this group.