Polar Climate - Tundra & Ice Caps
Polar climate has cold climatic conditions all through the year. Koppen classified Polar Climate as E type in his climatic classification. According to Koppen the summer temperature in this region is less than 10 degrees. He further divided the polar climate as Polar Tundra and Polar Ice Caps.
Polar Climate - Tundra & Ice-Caps
- The polar type of climate is primarily found north of the Arctic Circle in the northern hemisphere.
- The ice-caps are confined to Greenland and to the highlands of the high-latitude regions where the ground is permanently snow-covered.
- The lowlands which are ice-free for a few months have tundra vegetation.
- This includes the coastal strip of Greenland, the barren grounds of northern Canada and Alaska and the Arctic seaboard of Eurasia.
- In the southern hemisphere, the uninhabited land of Antarctica is the greatest single stretch of ice-cap where the layers of permanent ice are seen.
- A very low mean annual temperature characterizes the tundra or polar temperature.
- Only four months have a temperature above freezing point. The ground remains frozen for all but four months.
- Interiors are much colder than the coastal regions.
- Winters are long and very severe, summers are cool and brief.
- Beyond the Arctic and the Antarctic circles, there are weeks of continuous darkness.
- Frosts and blizzards that occur are very hazardous to the polar inhabitants.
- Precipitation is mainly in the form of snow, falling in winter and being drifted by the blizzards.
- Convectional rainfall is generally absent because of the low rate of evaporation and the lack of moisture in the cold polar air.
- In summer, there is a maximum and the precipitation is in the form of rain or sleet.
- Cyclones are felt in the coastal areas and there is a tendency towards a winter maximum.
- In severe environments like that of Tundra, few plants survive.
- The greatest inhibiting factor is the lack of heat and energy.
- The growing season is for less than three months and there are no trees in the tundra.
- Hence only lowest forms of vegetation are supported like mosses, lichens, and sedges.
- In the more sheltered spots, stunted birches, dwarf willows, and undersized alders struggle to survive.
- In the brief summers when snow melts and the days are warmer and longer, berry bushes and Arctic flowers bloom.
- They are short-lived but they brighten the monotonous polar landscape into Arctic prairies.
- Human activities in the polar regions are largely confined to the coast.
- The high altitude plateaus and mountains are uninhabitable as these are permanently snow-covered.
- The people lead a semi-nomadic life.
- Eskimos live in Greenland, northern Canada, and Alaska.
- Earlier they lived as hunters, fishers, and food-gatherers but in recent years they have started settling in permanent huts.
- During winter, they live in compact igloos and in summer they pitch portable tents of skins by the side of streams.
- Their food is derived from fish, seals, walruses and polar bears.
- In Eurasian tundra, other nomadic tribes like Lapps of northern Finland and Scandinavia, the Samoyeds of Siberia(from the Ural Mountains and the Yenisey Basin), the Yakuts from the Lena basin, the Koryaks and Chuckchi of north-eastern Asia live.
- They wander with their herds of reindeer across the Eurasian tundra where there are pastures.
- In USSR, large farms have been established for raising reindeer and for breeding fur-bearing animals.
Importance and Recent Development of the Arctic Region
- The Arctic region was once regarded as completely useless to mankind.
- But now the economic importance of the region has been recognized.
- Because of the discovery of minerals, new settlements have come up in the region.
- New railway lines have been constructed to bring shipments of ores mined to the major industrial districts.
- Ports have been established in the Arctic seaboard of Eurasia. Hence it has become possible to ship timber and fur from Siberia.