A polynya (common US spelling) or polynia (common UK spelling) (pronounced /pəˈlɪnjə/; from Russian: полынья, Russian pronunciation: [pəlɨˈnʲja] 'ice hole') is an area of open water surrounded by sea ice. Russian ( transliteration:,) is the most geographically widespread language of Eurasia, the most widely spoken of the Slavic languages Sea ice is formed from Ocean water that freezes Because the Oceans consist of Saltwater, this occurs at about -1 It is now used as geographical term for areas of sea in Arctic or Antarctic regions which remain unfrozen for much of the year. The Arctic is the Region around the Earth 's North Pole, opposite the Antarctic region around the South Pole. The term derives from the Russian word Полынья for a hole in the ice, and was adopted in the 19th century by polar explorers to describe navigable portions of the sea. [1]
Contents |
Formation
Polynyas are formed through two main processes:
- The first mechanism for polynya formation is thermodynamically driven, and occurs when the surface water temperature never reaches the freezing point. Freezing Point (Chinese 冰點 Bīngdiǎn is a news journal in the People's Republic of China which has been the subject of controversy over its criticism This may be due to a region of warm water upwelling, which reduces ice production and may stop it altogether. Upwelling is an oceanographic phenomenon that involves wind-driven motion of dense cooler and usually nutrient-rich water towards the ocean surface replacing the warmer This type of polynya is called a Sensible Heat Polynya.
- The second type of polynya is called a Latent Heat Polynya and is formed through the action of the wind or ocean currents which act to drive ice away from a fixed boundary, such as a coastline, fast ice, or an ice bridge. A katabatic wind, from the Greek word katabatikos meaning "going downhill" is the technical name for a drainage Wind, a wind An ocean current is continuous directed movement of Ocean water. The coast is defined as the part of the land adjoining or near the Ocean. Fast ice ( land-fast ice, landfast ice) is Sea ice that has frozen along Coasts ("fastened" to them along the Shoals or Ice bridge is sometimes used as a synonym for Ice road. An ice bridge is a frozen natural structure formed over Seas bays The polynya forms by initially the first year pack ice being driven away from the coast, which leaves an area of open water within which new ice is formed. Drift ice is Sea ice that floats on the surface of the water in cold regions as opposed to Fast ice, which is attached ("fastened" to a shore This new ice is then also herded downwind toward the first year pack ice. When it reaches the pack ice the new ice is consolidated onto the first year pack ice. The latent heat polynya is the open water region between the coast and the first year ice pack.
Latent heat polynyas are regions of high ice production and therefore are possible sites of dense water production in both polar regions. Earth's polar regions are the areas of the globe surrounding the poles also known as frigid zones. The high ice production rates within these polynyas leads to a large amount of brine rejection into the surface waters. This salty water then sinks and mixes to possibly form new water masses. An oceanographic water mass is an identifiable body of Water which has physical properties distinct from surrounding water It is an open question as to whether the polynyas of the Arctic can produce enough dense water to form a major portion of the dense water required to drive the thermohaline circulation. The Arctic is the Region around the Earth 's North Pole, opposite the Antarctic region around the South Pole. The term thermohaline circulation (THC refers to the part of the large-scale ocean circulation that is thought to be driven by global density gradients created by surface heat and
Ecology
Some polynyas, such as the North Water Polynya in Canada, occur seasonally at the same time and place each year. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page Because animals can adapt their life strategies to this regularity, these types of polynyas are of special ecological research significance. In winter, marine mammals such as walruses, narwhals and belugas that do not migrate south, remain there. Marine mammals are a diverse group of roughly 120 species of Mammal that are primarily Ocean -dwelling or depend on the ocean for food The walrus ( Odobenus rosmarus) is a large flippered Marine mammal with a discontinuous circumpolar distribution in the Arctic Ocean and The Narwhal ( Monodon monoceros) is an Arctic species of Cetacean. In spring, the thin or absent ice cover allows light in, through the surface layer as soon as the winter night ends, which triggers the early blooming of microalgae that are at the basis of the marine food chain. Microphytes are microscopic Algae, typically found in Freshwater and marine systems and are often called microalgae So, polynyas are suspected to be places where intense and early production of the planktonic herbivores ensure the transfer of solar energy (food chain) fixed by planktonic microalgae to Arctic cod, seals, whales, and polar bears. Food chains, also called food networks and/or trophic networks, describe the feeding relationships between species within an Ecosystem. The Arctic cod ( Arctogadus glacialis) is a deepwater fish closely related to the true Cod (genus Gadus) Pinnipeds ("fin-feet" lit "winged feet" or fin-footed mammals are a widely distributed and diverse group of semi-aquatic marine Mammals comprising Whales are marine mammals which are neither Dolphins (ie members of the families Delphinidae or Platanistoidae) nor Porpoises Orcas The polar bear ( Ursus maritimus) is a Bear native to the Arctic Ocean and its surrounding seas
Other uses of the term
The term may also refer to:
- Polynia, or Kane’s Polynia, an open sea around the North Pole that in the 19th century was rumored to exist. The North Pole, also known as the Geographic North Pole or Terrestrial North Pole, is subject to the caveats explained below defined as the point in the northern “The mystic Polynia, the open sea to the North of Siberia. ”[2] The search for this Polar Sea is related to, and comparable with that for the North-West Passage. The Northwest Passage is a sea route through the Arctic Ocean, along the northern coast of North America via waterways amidst the Canadian Arctic Archipelago [3]
- Polynia (ship): a ship crushed in sea ice in 1891, rescued by the Aurora, commemorated in the song Old Polina. Year 1891 ( MDCCCXCI) was a Common year starting on Thursday (link will display the full calendar of the Gregorian calendar (or a Common Russian-Japanese War She was one of three Pallada -class Cruisers built in St Old Polina is a traditional Newfoundland folk song. It is most likely based on the ship Polynia, built in 1861 of the Dundee Seal and Whale Fishing Company fleet
- Polynia Islands small low islands in Canada Northwest Territories on the Arctic Ocean, discovered by Francis Leopold McClintock and possibly named because of the sea-ice he observed inland on them. Country to "Dominion of Canada" or "Canadian Federation" or anything else please read the Talk Page The Northwest Territories (ˌnɔrθˌwɛstˈtɛrɨtɔriz ( NWT or NT; French, les Territoires du Nord-Ouest) is a territory The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region is the smallest and shallowest of the world's five major Admiral Sir Francis Leopold McClintock or Francis Leopold M'Clintock KCB ( 8 July, 1819 &ndash 17 November, 1907) was an [4] Close to Melville Island. Melville Island is a vast uninhabited member of the Canadian Arctic Archipelago, Canada with an area of.
- Polynia Lake on Melville Island. Melville Island is a vast uninhabited member of the Canadian Arctic Archipelago, Canada with an area of.
References
- ^ Sherard Osborn, Peter Wells, A Petermann Proceedings of the Royal Geographical Society of London Vol 12 no 2 1867-1868 pages 92-113 On the Exploration of the North Polar Region
- ^ Sherard Osborn Proceedings of the Royal Geographical Society of London, Vol. 16, No. 3. (1871 - 1872), pp. 227-241 On the Exploration of the North Polar Basin, with a Résumé of Recent Swedish, German and Austrian Attempts to Reach the Polar Circle from the Atlantic Ocean
- ^ John K. Wright Geographical Review, Vol. 43, No. 3. (Jul. , 1953), pp. 338-365 The Open Polar Sea
- ^ F. A. McDiarmid The Geographical Journal, Vol. 62, No. 4. (Oct. , 1923), pp. 293-302 Geographical Determinations of the Canadian Arctic Expedition
External links
- Weddell Polynya
- The American Heritage Dictionary of the English Language: Fourth Edition on "polynya"
- Polynya north of Alaska at NASA Earth Observatory
- Polynyas in the Bering and Chukchi Seas
Dapyx Software network: MP3 Explorer | Ebook Manager | Zenithic