Northern Asia

Map   Questions.

Show the Equator, Tropic of Cancer and Arctic Circle on the map of Asia. Climatic Contrasts. Asia extends from the equatorial regions in the south to the high-latitudinal regions of the Arctic in the north. It includes, therefore, all the climatic zones of the Northern Hemi­sphere. Its northern part lies in the frigid zone, its central, greater part in the temperate zone, its southern, peninsular and insular part in the torrid zone.

Fig. 84. Asia: Climatic regions
The enormous size of Asia produces great climatic contrasts within each zone. As the interior is far from the sea or is separated from it by mountains, it has mainly a continental climate. The re­gions open to the influence of the sea have a maritime climate.
The oceans and seas influence the climate of Asia in various ways. From the ice-clad Arctic Ocean arrive cold air masses that travel far inland. From the Pacific and Indian Oceans blow winds that cause heavy rains. The Pacific Ocean is crossed by a warm cur­rent that brings warmth to the shores of Asia.
The climate, moreover, depends on the altitude. The tall moun­tains, plateaus and lowlands have different climates, though they may lie in the same latitude.
Mountain ranges, whether they run in a latitudinal or longitu­dinal direction, serve as climatic boundaries. The regions on either side have different climates, either warm or cold, wet or dry.
The Climate of Northern Asia. In Northern Asia, as in Siberia, the climate is rigorous. The broad coastal belt of Northern Asia and the islands of the Arctic Ocean lie beyond the Arctic Circle, in the frigid zone. During the long arctic night the sun does not rise above the horizon. In summer the slanting rays of the sun hardly warm the earth. The rest of Siberia lies in the northern part of the temperate zone.
The cold air masses from the Arctic Ocean spread southward over Siberia without hindrance. The other oceans are either very distant (the Atlantic) or closed off by mountains (the Pacific and Indian). Under the clear, cloudless sky the surface of the earth cools rapidly. Siberian frosts are, therefore, sharper than those in the same latitudes of Europe.
Only in the coldest, north-eastern regions of Europe near the Northern Urals does the January isotherm reach 20°C below zero. In Asia this isotherm crosses the West Siberian Lowland and from there bends southward towards Central Asia. Further east, beyond the Yenisei, the January isotherm is 30°C below zero, and still

further east it reaches 40°C below zero. The bitter Siberian frosts are usually windless and, therefore, easier to endure.
The depressions in between the mountains of North-Eastern Siberia detain the cold masses of air, and the average January tem­perature in these areas drops to 50°C below zero. This is the coldest spot in the Northern Hemisphere, the so-called Cold Pole (Ver­khoyansk—Oimyakon).
The severest frost-ever recorded here was over 70°C below zero. Such frosts 'burn', and no clothing is protection enough against them.
Siberian summers are warm, the July temperatures being not lower, but even higher than those in the same latitudes of Europe. Thus, the variations between winter and summer temperatures are

even greater here than in Eastern Europe with its continental cli­mate.
Rainfall in Northern Asia is small. Evaporation from the Arctic Ocean is slight, while that from other oceans does not reach so far.
Thus, the wide variation in temperature here and the light rain­fall serve to show that Northern Asia has a sharp continental climate.
Questions and Assignments.

• Trace on the climate map the January isotherms crossing pa­
  rallel 60°N in Asia. Compare them with the isotherms of the same
  latitude in Europe.
• Study the map and determine the difference between the Ja­
  nuary and July temperatures in the 'Cold Pole' region.