Extreme cold wave in Siberia: breaking records

Siberia is a vast area stretching more than 3,000 km east of Moscow. Suffice it to say that, as seen from Oymyakon, the world’s coldest city in Eastern Siberia, Moscow appears to be in the west of the continent with an almost temperate climate.

Siberia: a cold hell

Every winter, Siberia is used to experiencing extreme values. In Yakutia, the coldest region, the average temperature in January is -45°C. This makes it the coldest area in the northern hemisphere, followed by some areas in northwestern Canada. It is also the 2nd coldest region on the planet in winter after Antarctica. However, the climate is very contrasting between winter and summer, with annual temperature variations reaching 80°C. In fact, in these sectors, which are -60° in winter, short bursts of heat can raise the temperature to 35°C.

Cold weather across the Eurasian continent

Every winter in Eastern Siberia, temperatures range from -50° to -55°C during the long arctic night, while temperatures do not exceed -30 to -40°C in the pale glow of a frosty day. However, since the beginning of January, the great cold has spread to almost all of Eurasia, from Moscow to Yakutia. The negative anomalies recorded in the heart of Siberia fell to -30°C more than the warm anomalies observed on our planet. Overall, the current temperature across Siberia makes it the strongest cold wave in Yakutia since 1982. But the minimum and maximum temperatures (-57°C at night, -50°C during the day) make it the strongest cold wave since 1994. Finally, -62°C recorded on Tuesday is a monthly record for Jilinda. station (since the opening of the current weather station in 1942).

Cold in Siberia © Weather Channel

Absolute cold records in Siberia are not under threat to date: -64 ° C in the Jilinda region, Batamay -65.7 ° C, Ulakhan Kyuel -65.2 ° C, Iema -65.0 ° C, Verkhoyansk -63.0 ° C , -62.1 °C, for example Oymyakon. The cold record that can be found in the archives in Russia dates back to January 26, 1926 with -67.8 ° C in Oymyakon and Verkhoyansk.

How to explain such a cold anomaly?

It may seem counterintuitive to observe such cold anomalies, which are also particularly intense in the northern hemisphere this winter during global warming. America’s Christmas chill dropped below 20°C on average, but only briefly. The current cold wave in Siberia is 30°C below average, so much so that weather maps no longer have the appropriate color. Conversely, warm anomalies are very widespread and long-lasting (often +10° to +14°C in North America as well as China today). Therefore, the contrasts are greater in the northern hemisphere and more moderate in the southern hemisphere.

January 10 global temperature anomalies © Climate Reanalysis

Mechanistically, the fluctuations of the jet stream are responsible for these effects of the basins, which transport temperate air to the north and cold air to the south. But this is not enough. Fluctuations in the tropopause, the layer that limits the troposphere we live in and the stratosphere above, may also partially explain this extreme cold. Variations in this boundary layer are capable of sinking the icy air of the stratosphere towards the ground. This principle is known in the media as the “polar vortex”. After this mechanism is activated, a strong anticyclone is activated and keeps the cold at ground level. This anticyclone is not new, it is known as the Siberian anticyclone.

The expected short-term meteorological evolution now shows that this cold front is gradually weakening and it will shift more towards Southeast Asia (China), which is currently experiencing unusually mild temperatures. After that, the temperature in Russia will reach the average season.

At the end, it appears that global warming is the main trend that has increased over the decades, but has not prevented the occurrence of cold epiphenomena. However, they remain less numerous than warm anomalies on a planetary scale, and this evolution should continue according to the climate scenarios presented by the IPCC.

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