Sudden Stratospheric Warming

The Sudden Stratospheric Warming phenomenon is part of polar amplification of global warming.

The Arctic is warming up more than twice as fast as the rest of the world, due to numerous feedbacks.

Early 2018 

The image below shows the situation on January 18, 2018, 15:00 UTC. The Polar Vortex has split into two parts, with one part centering over Bering Strait (left) and the other part centering over Fram Strait/Greenland (right), while the Polar Vortex is reaching speeds over the Arctic as high as 416 km/h or 259 mph (green circle).

The image below shows the situation on January 21, 2018. The Polar Vortex on the Northern Hemisphere has developed a third eye over the Mediterranean Sea and reaches speeds as high as 428 km/h or 266 mph over the North Sea. On the Southern Hemisphere, the Polar Vortex is located close to the Equator.

On February 9, 2018, four eyes were present, while the Polar Vortex reached speeds as high as 425 km/h or 263 mph over Greenland, reflecting increasingly extreme conditions due to global warming. Two images are added, the image below is a global projection.

The image below shows the Northern Hemisphere (orthographic=90,90) on February 9, 2018, when the Polar Vortex was split up into four vortices. As said above, winds at 10 hPa reached speeds as fast as 425 km/h or 264 mph (at the green circles on the images above and below).

Polar Vortex split up into 4 vortices
During February 10`8, a huge amount of heat had accumulated in the Arctic, as the NASA image below shows.

On February 16, 2018, the Polar Vortex has four eyes, with one eye centered over Alberta. The Polar Vortex reaches temperatures as high as 8.9°C or 47.9°F over Hudson Bay, and as low as -69.1°C or -92.5°F over the Pacific and -69.8°C or -93.6°F over the Atlantic. This huge temperature difference makes winds over Yukon Territory reach speeds as high as 328 km/h or 204 mph.

The image below shows Sudden Stratospheric Warming on February 16, 2018, when the Polar Vortex had split up into four vortices, as the Sudden Stratospheric Warming event unfolded.

Following the event, an atmospheric river of heat reached the North Pole; temperatures were as high as 1.1°C or 34.1°F on February 25, 2018, as illustrated by the image below.

The images below further illustrate the huge amount of heat that entered the Arctic from the south. Temperatures above 6°C were registered at Kap Morris Jesup, Greenland's northernmost weather station, on February 25, 2018.

Large areas over the Arctic Ocean can at times heat up strongly. The image below shows the higher latitudes reaching temperatures that are 30°C or 54°F higher than 1979-2000. 

Worryingly, very high methane releases followed this chain of events, likely originating from the seafloor of the East Siberian Arctic Shelf (ESAS), as discussed in the post Warning Signs

Early 2020

Besides an influx of heat, as occurred in February 2018, there are further events that can trigger methane releases from the seafloor of the Arctic Ocean. 

On the morning of March 12, 2020, peak methane levels were as high as 2902 ppb (parts per billion) at a pressure level of 469 mb (millibar, equivalent to an altitude of some 6 km (almost 20,000 feet).

What did cause this very high peak? The image on the right shows the situation at 695 mb.

High levels of methane, colored in magenta, show up over the oceans at high latitudes north, especially around Greenland and around Svalbard.

The image underneath on the right shows methane even closer to sea level, at 1000 mb. At this altitude, such magenta-colored high levels of methane only show up over an area in between Greenland and Svalbard.

It appears that these high methane levels did originate from this area. What could have triggered this?

The image below shows that an earthquake with a magnitude of 4.8 on the Richter scale hit an area in between Greenland and Svalbard on March 11, 2020, at 21:30:03 (UTC), 2020, at depth of 10 km.

It appears that the earthquake did cause destabilization of sediments at the seafloor of the Arctic Ocean in between Greenland and Svalbard, containing methane in the form of hydrates and free gas, with the destabilization resulting in the eruption of methane that subsequently reached the atmosphere.

The image on the right shows strong difference in pressure in the atmosphere over Greenland and over the Arctic Ocean on March 11, 2020, 21:00 UTC.

The next question is if there was something that triggered the earthquake.

The image below shows a forecast for March 22, 2020, of conditions in the stratosphere at 10 hPa.

Temperatures as high as 6.2°C or 43.2°F are forecast, and as low as -68.8°C or -91.9°F at another location, with wind reaching speeds as high as 369 km/h or 229 mph.

This indicates a strong updraft, carrying huge amounts of relatively warm air from low altitudes over the Arctic up into the stratosphere.

While Arctic sea ice extent is a bit larger than it was in previous years at this time of year, sea ice thickness is at a record low for the time of year.

These conditions may have acted as a sink plunger, triggering the earthquake and destabilizing sediments at the seafloor, resulting in the methane eruptions.

More generally, the events reflect a huge and growing overall imbalance in the temperature of the atmosphere, with the added methane releases further contributing to this imbalance.

[ Sep. 2020 anomaly, from earlier post ]
Sudden Stratospheric Warming late 2020

The maps on the right show what happened later in 2020, and in February 2021. 

Polar temperature anomalies were high in September 2020. Importantly, heatwave conditions were battering the north of Russia for months, setting up conditions for a Sudden Stratospheric Waring event. 

The next map underneath on the right shows the situation in November 2020. 

[ Nov. 2020 anomaly, from earlier post ]
Temperature anomalies were even higher, with anomalies as high as 12.9°C showing up over the Arctic Ocean and over the north of Russia. 

The Sudden Stratospheric Warming event reached a peak on December 30, 2020 03:00Z. 

Temperatures at 10 hPa (at the level of the stratospheric Polar Vortex) were as high as 5.4°C (or 41.6°F) and as low as -84.6°C (or -120.4 °F), indicating extreme temperature differences in the stratosphere (image below). 

[ Feb. 2021 anomaly, click to enlarge ]
The image on the right shows a relatively low temperature anomaly for February 2021 of 0.67°C, with some very cold areas showing up over North America and Russia.

As acknowledged by the WMO, the Sudden Atmospheric Warming event did contribute to more extreme weather with some very low temperatures temporarily showing up in some areas in February 2021.

The image below illustrates the severity of the Sudden Stratospheric Warming event. 

So, because a huge amount of hot air had moved up from surface level into the stratosphere over Russia, temperatures were lower than usual over Russia at surface levels in February 2021. 

At the same time, the heating of the Arctic Ocean continued, resulting in a decreased temperature difference between the North Pole and the Equator, in turn decreasing the speed at which hot air from around the Tropics moved toward the Arctic Ocean, making the Jet Stream more wavy which in turn enabled very cold air to descend from the Arctic deep down over North America and the north of Russia (see the above February 2021 anomaly map). 

In other words, the Sudden Atmospheric Warming event constituted a third mechanism distorting the Jet Stream, besides the two mechanisms discussed in a recent post


• Feedbacks in the Arctic

• Warning Signs

• Arctic Ocean January 2020

• Seismic Events

• Methane, Earthquake and Sudden Stratospheric Warming