What do surface currents affect

The ocean doesn't just store solar radiation; it also helps to distribute heat around the globe. When water molecules are heated, they exchange freely with the air in a process called evaporation.

Ocean water is constantly evaporating, increasing the temperature and humidity of the surrounding air to form rain and storms that are then carried by trade winds. In fact, almost all rain that falls on land starts off in the ocean. The tropics are particularly rainy because heat absorption, and thus ocean evaporation, is highest in this area.

Areas of coastal upwelling tend to be some of the most biologically productive areas in the ocean. Coastal upwelling is largely responsible for the lush kelp forests and productive fisheries found off the California coast Fig. There are areas of upwelling off the eastern and western shores of all continents. A coastal downwelling is the opposite of a coastal upwelling.

Warm surface water can be blown towards the shore by Ekman transport. This warm water mass pushes cold water down and away from the shore. Another kind of downwelling occurs when there is a buildup of the water in the center of a hurricane or in other low-pressure centers.

The term Langmuir circulation describes shallow water currents that rotate near the ocean surface and align with the direction of steady wind patterns Fig. In Fig. This acceleration of the current caused by wind over the water surface creates vortices and mixing of water surrounding these areas blue circles in Fig.

The vortices on either side of the wind flow rotate away from the center of the wind flow and are shown by the short gray arrows. This type of water circulation can be seen as long streaks or stripes in the water, sometimes with floating debris collecting between adjacent Langmuir currents Fig. Wind-driven Langmuir circulation plays an important roll in mixing water near the ocean surface.

Trade winds produce wind-generated currents in the tropics that travel from the eastern part of the Pacific and Atlantic ocean basins to the western part of the ocean basins.

These currents are called the Northern and Southern equatorial currents. The trade winds and equatorial currents pile up warm surface water in the western regions of basins. For example, the sea surface height at the western end of the Pacific is approximately 40 cm higher than at the eastern end.

This is similar to positioning a fan or hairdryer on one end of a tub filled with water. When the fan is turned on, the water level on the opposite side of the tub from the fan is much higher than near the fan.

This phenomenon is known as the basin-wide tilt Fig. In addition to an increase in sea surface height, the thermocline transition between warm surface water and cooler deep water is also affected. The warm, well-mixed layer of surface water is thicker in the western part than in the eastern part of ocean basins.

We have been discussing the global prevailing wind and ocean current patterns as they would appear in an ideal world Fig. But in the real world, these patterns are not always consistent.

For example, in a typical year strong trade winds push warm surface waters away from the coast of Peru near the equator, resulting in upwelling of cold, nutrient-rich waters. When the trade winds are reduced, the basin-wide tilt in the Pacific ocean basin is reduced, and warmer ocean water from the western Pacific flows back towards the typically colder eastern Pacific.

This current movement interferes with coastal upwelling as warm water replaces cold water, replacing normally nutrient rich water with nutrient-poor surface waters near the coast. This is largely due to an increase in trade wind strength that pushes warm surface waters further offshore than normal from Central and South America westward Fig. These stronger trade winds increase the degree of basin-wide tilt in the Pacific.

Fortunately, there are things we can do to help—like stop using plastic bags, straws, and bottles, recycling when we can, and disposing of waste properly. Use these classroom resources to teach about ocean plastics and check back for more coming later this year!

Scientists across the globe are trying to figure out why the ocean is becoming more violent and what, if anything, can be done about it. Ocean currents, including the ocean conveyor belt, play a key role in determining how the ocean distributes heat energy throughout the planet, thereby regulating and stabilizing climate patterns.

A current is the steady, predictable movement of a fluid within a larger body of that fluid. Fluids are materials capable of flowing and easily changing shape. A gyre is a circular ocean current formed by the Earth's wind patterns and the forces created by the rotation of the planet. Join our community of educators and receive the latest information on National Geographic's resources for you and your students. Skip to content. Image Rubber Duck on the Beach A rubber duck washed up on the beach after being carried out in the ocean.

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