Taken together, these larger and more permanent currents make up the systems of currents known as gyres. There are five major gyres: the North and South Pacific Subtropical Gyres, the North and South Atlantic Subtropical Gyres, and the Indian Ocean Subtropical Gyre.
What are the characteristics of subtropical gyres?
Subtropical gyres circle areas beneath regions of high atmospheric pressure. These are placid ocean areas thousands of kilometers in diameter. Unlike coastal zones, these central regions are relatively stable. The ocean water generally stays in one place while the currents of the gyre circulate around it.
Where are subtropical gyres located?
Five permanent subtropical gyres can be found in the major ocean basins—two each in the Atlantic and Pacific Oceans and one in the Indian Ocean—turning clockwise in the Northern Hemisphere and counterclockwise in the Southern.
How many subtropical gyres exist in the world’s oceans?
There are five subtropical gyres: North Pacific, South Pacific, North Atlantic, South Atlantic, and the Indian Ocean below the equator.
Which way do subtropical gyres flow?
Subtropical gyres
Circulation around the high pressure is clockwise in the northern hemisphere and counterclockwise in the southern hemisphere, due to the Coriolis effect. The high pressure in the center is due to the westerly winds on the northern side of the gyre and easterly trade winds on the southern side.
Why are subtropical gyres saline?
A combination of increasing direct evaporation over the regions with increasing remote evaporation over nearby E-P maxima is believed to be the main driver in increasing salinity of the subtropical oceans, suggesting an intensification of the global water cycle over decadal time scales.
What are the major components of the southern subtropical gyre in the Indian Ocean?
Subtropical gyres are made up of 4 main components:
Equatorial currents: either bordering north or south of a gyre, equatorial currents always move west along the equator and are set in motion by the trade winds.Western boundary currents: narrow, fast moving, turn because of the continents and Coriolis Effect.
How do gyres affect climate?
Ocean gyres are present in every ocean and move water from the poles to the equator and back again. The water warms at the equator and cools at the poles. Because ocean water temperatures can transfer to the air, the cold and warm waters circulated by the gyres influence the climate of nearby landmasses.
Why does water move downward in the middle of subtropical gyres?
This current is known as geostrophic flow. Driven by the long-term average winds in the subtropical highs, Ekman transport causes surface waters to move toward the central region of a subtropical gyre.
What is one impact of gyres on coastal climates?
Each gyre has a major effect on ocean circulation in that part of the ocean basin. As surface winds push the surface layer of the ocean with them, the surface wind gyres result in surface ocean current gyres. Along coastlines, the direction of movement of a gyre has a significant impact on continental climate.
Where is the Great garbage patch?
The Great Pacific Garbage Patch, also known as the Pacific trash vortex, spans waters from the West Coast of North America to Japan. The patch is actually comprised of the Western Garbage Patch, located near Japan, and the Eastern Garbage Patch, located between the U.S. states of Hawaii and California.
Why is North Pacific Gyre important?
The movement of the world’s major ocean gyres helps drive the “ocean conveyor belt.” The ocean conveyor belt circulates ocean water around the entire planet, making this an international problem. It is estimated that 1.15 to 2.41 million tonnes of plastic are entering the North Pacific ocean each year from rivers.
Where is the Sargasso Sea?
Sargasso Sea is located within the mythical Bermuda Triangle area with one of its corners Bermuda located on its western edge.
