Editing Oyashio Current

{{Short description|Cold subarctic ocean current in the Pacific Ocean}}
{{Redirect|Oyashio}}
[[File:Spring Bloom Colors the Pacific Near Hokkaido.jpg|thumb|The Oyashio Current colliding with the [[Kuroshio Current]] near [[Hokkaido]]. When two currents collide, they create [[Eddy (fluid dynamics)|eddies]]. [[Phytoplankton]] growing in the surface waters become concentrated along the boundaries of these eddies, tracing out the motions of the water.]]
[[File:Japan's ocean currents.PNG|thumb|The ocean currents surrounding the Japanese Archipelago: 1.[[Kuroshio]] 2. Kuroshio extension 3. Kuroshio countercurrent 4. The Tsushima Current 5. The Tsugaru Current 6. The Sōya Current '''7. Oyashio''' 8. [[:ja:リマン海流|The Liman Current]] ]]

The {{nihongo|'''Oyashio Current'''|親潮||"Parental Tide"}}, also known as the '''[[Sea of Okhotsk|Okhotsk]] Current''' or '''[[Kuril Islands|Kurile]] Current''', is a cold [[subarctic]] [[ocean current]] that flows south and circulates counterclockwise in the western North [[Pacific Ocean]].  The waters of the Oyashio Current originate in the [[Arctic Ocean]] and flow southward via the [[Bering Sea]], passing through the Bering Strait and transporting cold water from the Arctic Sea into the Pacific Ocean and the [[Sea of Okhotsk]].  It collides with the [[Kuroshio Current]] off the eastern shore of [[Japan]] to form the [[North Pacific Current]] (or Drift).
The nutrient-rich Oyashio is named for its metaphorical role as the {{nihongo|parent|親|''oya''}} that provides for and nurtures marine organisms.<ref>{{cite book|chapter= Kuroshio and Oyashio Currents|date=2001|last=Qiu|first=Bo|title=Encyclopedia of Ocean Sciences|pages=1413–25| publisher=Academic Press | url=http://www.soest.hawaii.edu/oceanography/bo/Q01.pdf |quote= The upwelled, nutrient-rich water feeds the Oyashio from the north and leads to its nomenclature, parent (''oya'') stream (''shio'').}}</ref><ref>{{cite book|last=Glattstein|first=Judy|title=Enhance Your Garden with Japanese Plants|url=https://books.google.com/books?id=BAhIAAAAYAAJ|year=1996|publisher=Kodansha International|isbn=978-1-56836-137-6|page=16 |quote=[...] currents whirl around and ascend, and nourish microscopic plankton. Oyashio is thus the parent of fishes.}}</ref>

==Climate impact==
The current has an important impact on the climate of the [[Russian Far East]], mainly in [[Kamchatka Peninsula|Kamchatka]] and [[Chukchi Peninsula|Chukotka]], where the northern [[tree line|limit of tree growth]] is moved south up to ten degrees compared with the latitude it can reach in inland [[Siberia]]. The waters of the Oyashio Current form probably the richest [[fishery]] in the world owing to the extremely high nutrient content of the cold water and the very high [[tides]] (up to {{convert|10.|m}}) in some areas – which further enhances the availability of nutrients. However, the Oyashio Current also causes [[Vladivostok]] to be the most equatorward [[port]] to seasonally freeze and require [[icebreaker|icebreaking ships]] to remain open in winter. Nonetheless, this has relatively little effect on the fish yield through the Sea of Okhotsk, because the large tides mean freezing does not occur so easily.

==History==
During [[glacial period]]s, when lower [[sea level]] exposed the [[Bering land bridge]], the current could not flow in the regions the Oyashio affects today. The level of cooling with the onset of glacial conditions (after an [[interglacial]]) was much less than in other areas of the Earth at similar latitudes. This allowed [[Tōhoku Region|Tōhoku]] and [[Hokkaidō]] – the only areas of [[East Asia]] with enough snowfall to potentially form glaciers – to remain unglaciated except at high elevations during periods when Europe and [[North America]] were largely glaciated. This lack of glaciation explains why, despite its present climate being much colder than most of [[Europe]], East Asia has retained 96 percent of [[Pliocene]] tree genera, whereas Europe has retained only 27%.{{citation needed|date=August 2017}}

== See also ==
* [[Oceanic gyres]]
* [[Physical oceanography]]

==References==
{{reflist}}
*Reddy, MPM (2001): ''Descriptive physical oceanography''. Taylor and Francis, {{ISBN|90-5410-706-5}}, pp 367–8.

==External links==
*[https://wedocs.unep.org/bitstream/handle/20.500.11822/8814/GIWA_regional_assessment_31_Oyashio_current.pdf?amp%3BisAllowed=&sequence=3  Regional Definition page for the Oyashio Current], UNEP Global International Waters Assessment (GIWA), accessed 26 July 2018

{{Ocean}}

[[Category:Currents of the Pacific Ocean]]
[[Category:Bering Strait]]
[[Category:Temperate Northern Pacific]]