Siberian anticyclone in November. Photo credit Reto Stöckli, NASA Earth Observatory.
The Siberian Frost High is a weather event that occurs in winter in northern Asia, particularly in the Siberian region. This is a high pressure area that forms in this region and can last for several weeks if not months.
This high pressure area is characterized by extremely cold temperatures that can fall below -50°C. The air flowing down Siberia’s anticyclone is very dry. Despite the high pressure, there can be light snowfall, fog and frost that deposits snow or very dry frost on the surface (powder snow).
The freezing Siberian anticyclone can have significant impacts on the environment and human life. Extremely low temperatures can cause problems for those who spend long periods outdoors, especially when the temperature drops many degrees below freezing, including frostbite and hypothermia. Also, dry air can cause breathing problems, especially in people with pre-existing lung problems.
The consequences of the freezing Siberian anticyclone are not only limited to human health, but also affect the economy and agriculture of the region. For example, extremely low temperatures limit harvest time to short periods and significantly reduce agricultural productivity.
The freezing Siberian anticyclone is caused by a combination of several factors. First, the Siberian region is characterized by high air pressure in winter. This is due to the cold temperature of the earth’s surface, which leads to an increase in atmospheric pressure near the ground. This anticyclone is known as the Siberian Russian and can reach very high pressures, the highest recorded
The world record is 1094.9 hPa measured in Bajdrag, Mongolia on December 28, 2020. Mongolia is heavily influenced by Siberian high pressure areas in winter.
Second, the freezing Siberian anticyclone is caused by the flow of cold air entering the region from the Arctic. This cold air flow is caused by the temperature difference between the Arctic and Siberia. The Arctic is initially colder than Siberia in early winter; the polar air moves toward Siberia and continues to cool because, unlike the North Pole, it is a landmass, while the Arctic is a vast sea, but within which is the perpetual polar pack ice.
Finally, the topography of the Siberian region plays an important role in the formation of the freezing anticyclone. The surrounding mountains can affect the airflow. The cold air slides down from the mountains in the very high pressure regimes and thermal inversions typical of such weather conditions and continues to cool in these areas thanks to the hood and low solar radiation.
The Siberian lowlands and low plateaux are much colder than the surrounding hills, even by 20°C.
The freezing Siberian anticyclone can also affect the global climate. Put simply, the resulting thermal energy can affect the global circulation of the atmosphere, changing ocean currents and weather conditions in the Northern Hemisphere and not only in Europe but also in North America and much more than we Europeans can imagine.
To monitor Siberia’s freezing anticyclone, meteorologists and various scientists use a variety of ground-based instruments. However, it must be said that Siberia has always been considered a marginal area, if not exploited by Russia for deposits, and the density of ground weather stations is very limited. However, in recent decades air mass estimates have also been performed by satellites, so we know much more than in the past.
The scarce availability of research weather stations significantly lowers the forecast of the weather of those air masses coming from Siberia, since data, so-called initialization data, start values, are necessary to obtain weather forecasts, but are quite scarce for this part of the world.
The frost in deep Siberia
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