Climate of Russia

Appendix 12.

Most of Russia has a harsh climate with long, cold winters and short, relatively cool summers. This is because Russia lies at high latitudes, and because high mountains along the country’s southern border block most maritime tropical air masses from penetrating Russia. During winter the moderating influence of the frozen Arctic Ocean is slight. Because most of the territory lies in a zone of westerly weather patterns, warm influences from the Pacific Ocean in the east do not reach far inland. This is particularly true in winter, when a large, cold high-pressure cell, which is centered in Mongolia, spreads over much of Siberia.

The primary marine influence comes from the Atlantic Ocean in the west, but by the time Atlantic air reaches Russia it has crossed the entire western part of Europe and undergone considerable modification. It penetrates the landmass most easily during summer, when a low-pressure system generally exists over the land. At that time warm, moist Atlantic air may push east well into central Siberia. This is the principal moisture-bearing air mass to reach Russia, and most of the territory consequently receives fairly high levels of summer precipitation. The summer precipitation is important for croplands, which need moisture during the growing season. In many areas, however, the distribution of rainfall during the summer is not advantageous. Drought often occurs in early summer, and middle and late summer may bring considerable rain and clouds that interfere with the harvest. This is particularly true in the far eastern region, where a monsoonal inflow of Pacific air occurs during middle and late summer. In northern regions, especially from Moscow northward, featureless, overcast skies are so frequent, particularly during winter, that Russians have named the phenomenon pasmurno, meaning "dull, dreary weather." During December, for instance, Moscow averages 23 days with overcast skies.

Most of the country has only light to modest precipitation, however. Across the Great European Plain, average annual precipitation decreases from more than 800 mm (32 in) in western Russia to less than 400 mm (16 in) along the Caspian Sea coast. Throughout Siberia, annual precipitation generally ranges from 500 to 800 mm (20 to 32 in), with precipitation amounts generally less than 300 mm (12 in) in northeastern Siberia. At higher elevations annual totals may reach 1,000 mm (40 in) or more, but in interior basins precipitation may total less than 300 mm (12 in).

Russia’s climate is characterized by temperature extremes. The coldest winter temperatures occur in eastern Siberia, while air from the Atlantic Ocean tempers conditions somewhat in the west. Verkhoyansk in the northeast is often called the "cold pole of the north." During January, temperatures there average -51°C (-59°F), and they have reached a low of -68°C (-90°F) in February. The same conditions that make for cold temperatures during winter—isolation from the sea and narrow valleys between mountains—produce air stagnation in summer. Furthermore, because Verkhoyansk is so far north, it experiences nearly continuous daylight hours in summer. During July temperatures in Verkhoyansk average 13°C (56°F) and have reached as high as 37°C (98°F). The city has an absolute temperature range (the difference between the coldest and hottest recorded temperatures) of 105° Celsius degrees (188° Fahrenheit degrees), by far the greatest temperature range on Earth.

Russia encompasses a number of distinct climate zones, which generally extend across the country in east-west belts. A polar desert climate exists on several of the Arctic islands, such as the northernmost portions of Novaya Zemlya and Severnaya Zemlya. Along the Arctic coast a tundra climate prevails and extends south in the far eastern region on upper mountain slopes for 100 km (60 mi) or more. To the south of this zone is a broad belt of subarctic climate that extends south to the city of Saint Petersburg and broadens east of the Urals to envelop almost all of Siberia.

Most of European Russia has a more temperate continental climate. This belt is widest in the west. It stretches from the Baltic Sea to the Black Sea, then tapers eastward to include a narrow strip of the southern West Siberian Plain; it is also found in the extreme southeastern portion of Russia. Temperatures in Moscow, which lies in the continental climate zone, range from -13° to -6°C (9° to 21°F) in January and from 13° to 24°C (56° to 75°F) in July. Temperatures in Vladivostok, in the southern part of far eastern Russia, range from -17° to -9°C (1° to 16°F) in January and from 15° to 20°C (59° to 69°F) in July.

A broad belt of drier steppe climate with cold winters begins along the Black Sea coast and extends northeast across the North Caucasian Plain, the lower Volga Valley, the southern Urals, and southwestern Siberia. It continues eastward in isolated mountain basins along the extreme fringes of Siberia.

Дата добавления: 2014-12-27