What are the characteristics of the polar regions?

BBC Bitesize – tundra (polar regions)

BBC Class Clips – flora and fauna in the tundra

BBC Class Clips – flora and fauna in the polar regions

Antarctica and the Arctic have distinctive characteristics

  The Arctic Antarctica Climate

  • Average summer temperatures <10c
  • Winter temperatures around -20c to -40c
  • Annual precipitation <500mm
  • Winds blow strongly
  • Colder than the Arctic
  • Summer temperatures around -20c to -5c
  • Winter temperatures can reach almost -90c
  • Annual precipitation is lower, around 50mm inland and 200mm on the coast
  • Windiest continent

Features of the land and sea

  • Majority of the Arctic is made up of ocean, lots of drifting ice packs and iceberg. Sea ice extends further in winter
  • On land there are mountainous regions, areas that are permanently covered with snow and ice, and areas of treeless tundra (where only a surface layer of the soil thaws each summer)
  • Large areas of permafrost (ground which has been frozen for a few years). When the top few centimetres thaw it produces a landscape with many depressions which fill with lakes. Marshland and boggy ground cover large areas. The soil flows when it thaws out and is not stable.
  • Continent (land mass) which is 99% covered by an ice sheet
  • A few mountains poke out of the top of the ice sheet (nuntaks) e.g. Transantarctic Mountains
  • Sea freezes in winter, nearly doubling the size of the continent

Flora and fauna

  • Whales, seals, fish, wolves, polar bears, reindeer, caribou and lots of birds
  • Most animals have adapted to specific conditions of the Arctic (sub-zero temperatures and absence of liquid water)
  • Low-growing shrubs, lichen, moss, some flowering plants e.g. Arctic poppies
  • Plants like dwarf willow and lichens cling to the ground surface to avoid being damaged by strong winds.
  • Some species have natural ‘anti-freeze’
  • Southern fringes of the Arctic have taiga, large expanses of coniferous forest but these disappear with distance north along a line called the tree line
  • Less vegetation than the Arctic, there are two species of grass which are found in a few places, otherwise only algae and lichen can survive
  • Sea contains lots of phytoplankton

Whales, seals, penguins, sea-birds

  • All animals rely on the sea e.g. for food or to provide a habitat for breeding
  • Penguins nest on ice shelves and Emperor penguins spend the winter there as well. Most other species migrate north to avoid the extremes of the winter cold
  • Marine creatures, including penguins, avoid the extreme temperatures found inland so most biodiversity is found at sea or around the coast

Water and nutrient cycles

Image result for water and nutrient cycle tundraImage result for nutrient cycle tundra