During the winter the vast plains of the Eurasian continent are subject to a strong cooling of temperature. This marked cooling is facilitated by a series of predisposing factors; Central and Eastern Siberia, as well as Mongolia, they remain extremely far from the mitigating influence of the sea, here during the winter the temperature can cool down without obstacles but how do you get to such high pressure values as those recorded yesterday in the steppes of Mongolia?
The development of the so-called “Russian-Siberian anticyclone” is rooted in the first outbreaks of Arctic air that occur in this region during the autumn months. The arrival of snow on large areas of the Siberian plain, promotes radiative cooling during the long winter nights. During the day the snow-covered and frozen soils, amplify the albedo effect, the snowpack reflects the sun’s rays in the upper atmosphere and the temperature of the air cannot heat up.
The coldest air masses remain trapped in the lower layers of the atmosphere, in the heart of the winter season on these lands the temperatures can become extremely cold. The increase in atmospheric pressure in this case is not answered by the presence of an anticyclone of a dynamic nature, i.e. governed by a mass of hot air – but it is the result of the weight of the cold air itself which being very dense, causes an increase in atmospheric pressure.
The record values that have been registered Tuesday 29 December on Mongolia, are the most tangible manifestation of a complete thermalization of the high pressure on the Eurasian steppes. Here we have extremely cold air on the ground. Who knows if even a small portion of this cold air doesn’t have the strength to reach Europe during the winter?
In the meantime, we let you reflect on these incredible atmospheric pressure values.
1090,4 hPa a Gandan Huryee
1091,3 hPa a Nömrög
1091,7 hPa in Bayan-Uul
1092,4 hPa a Bayanbulag
1093,6 hPa a Tosontsengel
1094,3 hPa a Tsetsen Uul
1094,9 hPa a Bajdrag
These data were disseminated by Géoclimat.
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