At a coastal upwelling zone, wind blow parallel to a coast, water at the ocean surface moves away from the coast and deep water rises up to take its place. Courtesy of NOAA

In areas of upwelling, deep ocean water makes its way to the surface. This has an impact on marine life as well as the region's climate.

Upwelling happens commonly along coastlines. Winds blowing parallel to a coastline cause water at the ocean surface to moves at about a 90 degrees angle from the wind direction (to the right of the wind direction in the Northern Hemisphere and to the left of the wind direction in the Southern Hemisphere) because of a process called Ekman transport. In places where surface waters are moved away from a coast by this process, water rises up from deeper in the ocean to take its place.

The water that is moved up to the surface is usually cold and rich in nutrients like nitrogen and phosphorus, which come from the decomposing bodies of dead sea creatures. Once at the surface, these extra nutrients are snatched up by phytoplankton, tiny photosynthesizing plants that float in the ocean water. Plankton populations often grow quickly in upwelling areas, a phenomenon called a plankton bloom. Tiny floating animals called zooplankton eat the phytoplankton and fish eat the zooplankton, making upwelling areas rich with marine life. About half the fish caught in the world comes from upwelling zones.

Upwelling also happens as a part of El Niño (ENSO) events in the Pacific Ocean off the coast of Ecuador and Peru and this has far-reaching effects on weather, changing precipitation patterns in many areas of the world.

Downwelling is the opposite of upwelling - surface waters pushing down into deeper areas of the ocean. This happens when winds cause Ekman transport to push water toward a coast and then deeper in the ocean.

At a coastal upwelling zone, wind blow parallel to a coast, water at the ocean surface moves away from the coast and deep water rises up to take its place. Courtesy of NOAA

There are places in the ocean where water from the deep sea travels up to the surface. These are called areas of upwelling. The deep waters can have a large influence upon life in the ocean and the climate too.

Upwelling often happens where wind blows along a coastline. The wind causes the water at the ocean surface to move perpendicular to it, away from the coast, because of a process called Ekman transport. When surface water moves away from the coast, water from deeper in the ocean rises up and takes its place.

The water that is moved up to the surface is usually cold and rich in nutrients, which come from the rotting bodies of dead sea creatures that sunk into deep water. When the deep water gets to the surface, these extra nutrients are snatched up by plankton that floats in the ocean. The number of plankton grows where there is upwelling. Tiny animals gobble up the plankton and fish eat the tiny animals. This means that upwelling areas are full of marine life. About half the fish caught in the world comes from places where there is upwelling.

Upwelling also happens as a part of El Niño (ENSO) events in the Pacific Ocean off the coast of Ecuador and Peru. This has an impact on weather, changing the pattern of precipitation in many areas of the world.

Downwelling is the opposite of upwelling - surface waters pushing down into deeper areas of the ocean. This happens when winds cause Ekman transport to push water toward a coast and then deeper in the ocean.

At a coastal upwelling zone, wind blow parallel to a coast, water at the ocean surface moves away from the coast and deep water rises up to take its place. Courtesy of NOAA

There are places in the ocean where water from the deep sea travels up to the surface. These are called areas of upwelling. The deep waters can have a large influence on marine life and the climate too.

Upwelling can happen where wind blows along a coast. The wind causes water at the ocean surface to move away from the coast. When surface water moves away from the coast, water from deeper in the ocean rises up and takes its place.

The water that is moved up to the surface is usually cold and rich in nutrients. When the deep water gets to the surface, these extra nutrients are snatched up by plankton that floats in the ocean. Tiny animals gobble up the plankton and fish eat the tiny animals. This means that upwelling areas are full of marine life.

Upwelling also happens as a part of El Niño (ENSO) events in the Pacific Ocean off the coast of Ecuador and Peru. This has an impact on weather, changing where and when rain falls in many areas of the world.

Downwelling is the opposite of upwelling - surface waters pushing down into deeper areas of the ocean. This happens when winds cause water to push toward a coast and then deeper in the ocean.