Jet streams are fast flowing,narrow air currents in the Earth's atmosphere.
The Barents Sea is a marginal sea of the Arctic Ocean,located off the northern coasts of Norway and Russia and divided between Norwegian and Russian territorial waters. It was known earlier among Russians as the Northern Sea,Pomorsky Sea or Murman Sea;the current name of the sea is after the historical Dutch navigator Willem Barentsz.
The cryosphere is an umbrella term for those portions of Earth's surface where water is in solid form. This includes sea ice,ice on lakes or rivers,snow,glaciers,ice caps,ice sheets,and frozen ground. Thus,there is a overlap with the hydrosphere. The cryosphere is an integral part of the global climate system. It also has important feedbacks on the climate system. These feedbacks come from the cryosphere's influence on surface energy and moisture fluxes,clouds,the water cycle,atmospheric and oceanic circulation.
The ringed seal is an earless seal inhabiting the Arctic and sub-Arctic regions. The ringed seal is a relatively small seal,rarely greater than 1.5 metres (5 ft) in length,with a distinctive patterning of dark spots surrounded by light gray rings,hence its common name. It is the most abundant and wide-ranging ice seal in the Northern Hemisphere,ranging throughout the Arctic Ocean,into the Bering Sea and Okhotsk Sea as far south as the northern coast of Japan in the Pacific and throughout the North Atlantic coasts of Greenland and Scandinavia as far south as Newfoundland,and including two freshwater subspecies in northern Europe. Ringed seals are one of the primary prey of polar bears and killer whales,and have long been a component of the diet of indigenous people of the Arctic.
Sea ice arises as seawater freezes. Because ice is less dense than water,it floats on the ocean's surface. Sea ice covers about 7% of the Earth's surface and about 12% of the world's oceans. Much of the world's sea ice is enclosed within the polar ice packs in the Earth's polar regions:the Arctic ice pack of the Arctic Ocean and the Antarctic ice pack of the Southern Ocean. Polar packs undergo a significant yearly cycling in surface extent,a natural process upon which depends the Arctic ecology,including the ocean's ecosystems. Due to the action of winds,currents and temperature fluctuations,sea ice is very dynamic,leading to a wide variety of ice types and features. Sea ice may be contrasted with icebergs,which are chunks of ice shelves or glaciers that calve into the ocean. Depending on location,sea ice expanses may also incorporate icebergs.
In glaciology,an ice cap is a mass of ice that covers less than 50,000 km2 (19,000 sq mi) of land area. Larger ice masses covering more than 50,000 km2 (19,000 sq mi) are termed ice sheets.
A circumpolar vortex,or simply polar vortex,is a large region of cold,rotating air;polar vortices encircle both of Earth's polar regions. Polar vortices also exist on other rotating,low-obliquity planetary bodies. The term polar vortex can be used to describe two distinct phenomena;the stratospheric polar vortex,and the tropospheric polar vortex. The stratospheric and tropospheric polar vortices both rotate in the direction of the Earth's spin,but they are distinct phenomena that have different sizes,structures,seasonal cycles,and impacts on weather.
Ice algae are any of the various types of algal communities found in annual and multi-year sea,and terrestrial lake ice or glacier ice.
The Norwegian Current is one of two dominant arctic inflows of water. It can be traced from near Shetland,north of Scotland,otherwise from the eastern North Sea at depths of up to 100 metres. It finally passes the opening into the Barents Sea,a large outcrop of the Arctic Ocean. Compared to its partial source the North Atlantic Current it is colder and less salty;the other sources are the less saline North and Baltic seas and the Norwegian fjords and rivers. It is considerably warmer and saltier than the Arctic Ocean,which is freshened by precipitation and ice in and around it. Winter temperatures in the flow are typically between 2 and 5 °C —the co-parent North Atlantic flow,a heat remnant of its Gulf Stream chief contributor,exceeds 6 °C.
Due to climate change in the Arctic,this polar region is expected to become "profoundly different" by 2050. The speed of change is "among the highest in the world",with the rate of warming being 3-4 times faster than the global average. This warming has already resulted in the profound Arctic sea ice decline,the accelerating melting of the Greenland ice sheet and the thawing of the permafrost landscape. These ongoing transformations are expected to be irreversible for centuries or even millennia.
Polar amplification is the phenomenon that any change in the net radiation balance tends to produce a larger change in temperature near the poles than in the planetary average. This is commonly referred to as the ratio of polar warming to tropical warming. On a planet with an atmosphere that can restrict emission of longwave radiation to space,surface temperatures will be warmer than a simple planetary equilibrium temperature calculation would predict. Where the atmosphere or an extensive ocean is able to transport heat polewards,the poles will be warmer and equatorial regions cooler than their local net radiation balances would predict. The poles will experience the most cooling when the global-mean temperature is lower relative to a reference climate;alternatively,the poles will experience the greatest warming when the global-mean temperature is higher.
The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately 14,060,000 km2 (5,430,000 sq mi) and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean,although some oceanographers call it the Arctic Mediterranean Sea. It has also been described as an estuary of the Atlantic Ocean. It is also seen as the northernmost part of the all-encompassing world ocean.
The Fram Strait is the passage between Greenland and Svalbard,located roughly between 77°N and 81°N latitudes and centered on the prime meridian. The Greenland and Norwegian Seas lie south of Fram Strait,while the Nansen Basin of the Arctic Ocean lies to the north. Fram Strait is noted for being the only deep connection between the Arctic Ocean and the World Oceans. The dominant oceanographic features of the region are the West Spitsbergen Current on the east side of the strait and the East Greenland Current on the west.
The West Spitsbergen Current (WSC) is a warm,salty current that runs poleward just west of Spitsbergen,,in the Arctic Ocean. The WSC branches off the Norwegian Atlantic Current in the Norwegian Sea. The WSC is of importance because it drives warm and salty Atlantic Water into the interior Arctic. The warm and salty WSC flows north through the eastern side of Fram Strait,while the East Greenland Current (EGC) flows south through the western side of Fram Strait. The EGC is characterized by being very cold and low in salinity,but above all else it is a major exporter of Arctic sea ice. Thus,the EGC combined with the warm WSC makes the Fram Strait the northernmost ocean area having ice-free conditions throughout the year in all of the global ocean.
The Arctic dipole anomaly is a pressure pattern characterized by high pressure on the arctic regions of North America and low pressure on those of Eurasia. This pattern sometimes replaces the Arctic oscillation and the North Atlantic oscillation. It was observed for the first time in the first decade of 2000s and is perhaps linked to recent climate change. The Arctic dipole lets more southern winds into the Arctic Ocean resulting in more ice melting. The summer 2007 event played an important role in the record low sea ice extent which was recorded in September. The Arctic dipole has also been linked to changes in arctic circulation patterns that cause drier winters in Northern Europe,but much wetter winters in Southern Europe and colder winters in East Asia,Europe and the eastern half of North America.
The Barents Sea Opening (BSO) is an oceanographic term for the Western Barents Sea,the sea area between Bear Island in the south of Svalbard and the northern extremity of Norway through which a water mass of Atlantic origin flows into the Arctic Ocean. The inflow of relative warm water into the Arctic Ocean occurs not only through the Barents Sea Opening,but also through Fram Strait which is much deeper. The internal energy entering the colder waters has an influence on the atmosphere and the sea ice above and therefore possibly on the global climate.
Sea ice in the Arctic region has declined in recent decades in area and volume due to climate change. It has been melting more in summer than it refreezes in winter. Global warming,caused by greenhouse gas forcing is responsible for the decline in Arctic sea ice. The decline of sea ice in the Arctic has been accelerating during the early twenty-first century,with a decline rate of 4.7% per decade. Summertime sea ice will likely cease to exist sometime during the 21st century.
Cecilia M. Bitz is an American climatologist known for her research on sea ice and high-latitude climate change. She is a professor and chair in the Atmospheric Sciences Department,as well as the director of the Program on Climate Change at the University of Washington. She was featured on NPR's All Things Considered segment to speak about factors that lead to sea ice loss in 2007,and testified before the United States Senate committee of Energy and Natural Resources on arctic opportunities in 2015.
Atlantification is the increasing influence of Atlantic water in the Arctic. Warmer and saltier Atlantic water is extending its reach northward into the Arctic Ocean. The Arctic Ocean is becoming warmer and saltier and sea-ice is disappearing as a result. The process can be seen on the figure on the far right,where the sea surface temperature change in the past 50 years is shown,which is up to 5 degrees in some places. This change in the Arctic climate is most prominent in the Barents Sea,a shallow shelf sea north of Scandinavia,where sea-ice is disappearing faster than in any other Arctic region,impacting the local and global ecosystem.
Patricia Ana Matrai is a marine scientist known for her work on the cycling of sulfur. She is a senior research scientist at Bigelow Laboratory for Ocean Sciences.
