Oyashio

From Glossary of Meteorology



Oyashio

The western boundary current of the North Pacific subpolar gyre.

Fed by the Alaskan Stream and Kamchatka Current, the Oyashio flows southward along the Kuril Islands and the east coast of northern Japan to 39°–40°N and occasionally as far south as 36°N. Near southern Hokkaido (43°N) the current splits into two branches known as the First and Second Oyashio Intrusion. In the region east of Tsugaru Strait (41°N) it is dominated by eddies; one or two cyclonic (warm core) eddies are formed each year. Every six years or so one of them grows into a giant eddy that then dominates the region for a year. Farther downstream the Oyashio meets the northward flowing Kuroshio to form the Arctic Polar Front. Both currents maintain their own frontal systems, the Oyashio Front being characterized by temperatures of 2°– 8°C and feeding into the Aleutian Current, while the Kuroshio Front has temperatures of 10°– 15°C and feeds into the North Pacific Current.


Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.