Voyeykov axis

Named after climatologist Alexander Voeikov , who investigated this phenomenon. He himself called it the main axis of the mainland ^[1] . Also known in the literature under the names "barometric axis of Voyeykov" and "climatic axis of Voyeykov." Sometimes referred to as the axis of Voyeykov- Brownov .

A.I. Voeikov was closely engaged in the study of atmospheric circulation in the early 70s of the XIX century, while actively traveling. At the end of 1872 he was sent to the United States. Along the way, he visits a number of European cities: Vienna, Berlin, Gotu, Utrecht, London. In Gotha, Voejkov is preparing for publication a work on atmospheric circulation, which is published in 1874 in German under the title Die atmosphärische Zirkulation in the Appendix to . In early 1873 he travels to the United States, where he visits New York, Boston, New Haven and Washington.

In Washington, Voeikov meets with the Secretary of the Smithsonian Institution Henry, who proposes to finish the work on the winds of the globe, begun by the deceased Professor Coffin ^[2] . For this work, Voeikov spent the whole autumn of 1873. The new material allowed a new approach to the described phenomenon. Voeikov expanded the available analysis of the relationship between wind and pressure, supplementing it with climatological conclusions about the role of the Siberian anticyclone and its spur extended to Europe ^[3] .

The formation of the Voeikov axis is related to the continental climate in the interior of Eurasia. In winter, the territories of Mongolia and Siberia experience strong cooling. This leads to the formation of a stable maximum of atmospheric pressure - the Siberian anticyclone . Its formation is promoted not only by the enormous dimensions of the mainland, but also by the relief of the earth's surface. In Tuva and northern Mongolia, there are vast hollows and valleys surrounded by high mountain ranges. In winter, stagnation of chilled air occurs in them, which favors an increase in atmospheric pressure.

From the territory of Mongolia and the south of Siberia, the high-pressure area diverges in the form of two languages ​​(spurs) in two directions - in the north and west. The East Siberian anticyclone goes north. It is connected with clear, quiet and very frosty weather, which is established in winter in the vastness of Eastern Siberia. The Voeikov axis extends westward, which can be traced in Kazakhstan and in the south of the East European Plain. It runs approximately along the Kyzyl-Uralsk-Saratov-Kharkov-Chisinau line. To be more precise, in this segment it passes through the watershed of the Urals and Ilek , through Uralsk along the Saratov Trans-Volga region a little south of Marx , on the right bank of the Volga, it rises sharply to 52 degrees north latitude, a little south of Petrovsk it goes west to the Turki region, after which it decreases to the southwest, passing 20-25 km north of Balashov and 10-15 km north of Borisoglebsk , through the Liskinsky district and the southeast of the Belgorod region, and passing in the Kharkov region, leaves for Moldova . To the west of Moldova, it continues, gradually weakening, up to southern France, where the effect of another center of high pressure - the Azores anticyclone - is already felt.

In winter, on the territory of Eurasia, the Voeikov axis plays an important climate-forming role, being a large wind section. In winter, north and southwest of the axis prevail westerly and southwest winds. In the north of the East European Plain, the action of the Voeikov axis is emphasized by the Icelandic minimum . Their proximity here is enhanced by western transport , which carries moist and relatively warm air masses. South of the Voyeykov axis, northeast and east winds blow. They carry dry and cold continental air of temperate latitudes from the Asian maximum.

In the summer, the maximum high pressure over Mongolia disappears. In this case, the Voyeykov axis remains in a weakened state, but loses its wind-severing value. During this period, it is no longer supported by the Siberian anticyclone, but by the Azores anticyclone, from the side of which anticyclones move east ^[4] .

The Voeikov axis is not only a wind and climate separation. Other major natural boundaries are associated with it. On the East European Plain, near the Voeikov axis, the boundary between the forest-steppe and the steppe passes ^[5] . This fact was first noticed by L. S. Berg ^{[6] [7] [8]} .