An ocean gyre is a large system of circular ocean currents formed by global wind patterns and forces created by Earth’s rotation.
Three forces cause the circulation of a gyre: global wind patterns, Earth’s rotation, and Earth’s landmasses. Wind drags on the ocean surface, causing water to move in the direction the wind is blowing.
Earth’s rotation deflects, or changes the direction of, these wind-driven currents. This deflection is a part of the Coriolis effect. The Coriolis effect shifts surface currents by angles of about 45 degrees. In the Northern Hemisphere, ocean currents are deflected to the right, in a clockwise motion. In the Southern Hemisphere, ocean currents are pushed to the left, in a counterclockwise motion. Earth’s continents and other landmasses (such as islands) also influence the creation of ocean gyres.
Types of Gyres
- There are three major types of ocean gyres based on the location : tropical, subtropical, and subpolar.
- North Pacific Gyre is consists of North equatorial current, Kuroshio current, North Pacific current and California current.
- South Pacific Gyre is consists of South equatorial current, East Australian current, Antarctic Circumpolar current and Peru current.
- North Atlantic Gyre is consists of North equatorial current, Gulf stream, North Atlantic current and Canary current.
- South Atlantic Gyre is consists of South Equatorial current, Brazil current Antarctic Circumpolar current and Benguela current.
- Indian ocean Gyre is consists of South equatorial current, Agulhas current, Atlantic Circumpolar current and West Australian current.
References :
- https://education.nationalgeographic.org/resource/ocean-gyre/
- https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQQQRDaM5ib_pZOc2c1O0e51kTkygISNCZke4pTsLT7huEXp1LcziUjnSoWTTZldMrQhHY&usqp=CAU
- https://rwu.pressbooks.pub/app/uploads/sites/7/2019/05/figure9.1.2.png