Why is upwelling an important process in a marine ecosystem?
The deeper water that rises to the surface during upwelling is rich in nutrients. These nutrients “fertilize” surface waters, encouraging the growth of plant life, including phytoplankton. Upwelling can also play an important role in the movement of marine animals.
Where are large areas of consistent upwelling found in the oceans?
Upwelling is most common along the west coast of continents (eastern sides of ocean basins). In the Northern Hemisphere, upwelling occurs along west coasts (e.g., coasts of California, Northwest Africa) when winds blow from the north (causing Ekman transport of surface water away from the shore).
Where can you find upwelling areas in the world?
Therefore, good fishing grounds typically are found where upwelling is common. For example, the rich fishing grounds along the west coasts of Africa and South America are supported by year-round coastal upwelling. Seasonal upwelling and downwelling also occur along the West Coast of the United States.
What happens as a result of upwelling?
Upwelling is a process in which deep, cold water rises toward the surface. Water that rises to the surface as a result of upwelling is typically colder and is rich in nutrients. These nutrients “fertilize” surface waters, meaning that these surface waters often have high biological productivity.
What three types of fish are found almost entirely in upwelling regions?
The cool, nutrient-filled water in upwelling currents support blooms of algae and seaweed, the base of the food chain for many clams, crustaceans, and fish. Herring, anchovy, and sardines, three of the most widely harvested fish, are especially concentrated in upwelling zones.
Does salinity have an effect on upwelling?
As a result, upwelled water with high salinity and low temperature is warmed up due to downward surface heat fluxes while it is transported offshore by the Ekman transport.
How does upwelling affect climate?
Again, deeper water comes to the surface bringing with it nutrients and cooler water temperatures. In some places, upwelling can even affect the weather. In places such as San Francisco, the cool water temperatures brought by upwelling can cause air temperatures to drop and result in even more dense fog.
What is the cause and effect of upwelling?
Upwelling is a process in which currents bring deep, cold water to the surface of the ocean. Upwelling is a result of winds and the rotation of the Earth. The Earth rotates on its axis from west to east. Because of this rotation, winds tend to veer right in the northern hemisphere and left in the southern hemisphere.
What effect does El Niño have on upwelling?
During an El Niño event, the easterly trade winds converging across the equatorial Pacific weaken. This in turn slows the ocean current that draws surface water away from the western coast of South America and reduces the upwelling of cold, nutrient–rich water from the deeper ocean, flattening out the thermocline.
Why are huge schools of fish usually found in zones of upwelling?
Upwelling is often caused by the wind when it blows the surface water away. Huge schools of fish are often found in upwelling zones. The reason for this event is because the upwelling zones are rich in nutrients, which came from the deepest ocean zones.
How does downwelling occur?
Downwelling occurs when the water on the surface of the sea becomes denser than the water beneath it and so it sinks. Most downwelling happens at the poles. There, cold air chills the water.
What is the relationship between the cold current upwelling and the primary productivity?
Upwelling occurs when surface waters diverge (move apart), enabling upward movement of water. Upwelling brings water to the surface that is enriched with nutrients important for primary productivity (algal growth) that in turn supports richly productive marine ecosystems.
Which gives rise to equatorial upwelling?
Equatorial upwelling is the process where trade winds at the Equator blow surface water both north and south, allowing upwelling of deeper water. The trade winds converge near the equator and the consequent Ekman transport away from the equator gives rise to upwelling.
What is a Geostrophic gyre?
The horizontal movement of surface water arising from a balance between the pressure gradient force and the Coriolis force is known as geostrophic flow. As noted earlier, viewed from above, geostrophic flow in a subtropical gyre is clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere.
How does upwelling affect the weather of a coastal region?
During upwelling, cold water in the ocean is stirred up and brought to the surface. When the air is carried landward towards the coast, it leads to rainfall when the saturated air releases the water. The air then becomes cold and dry and it rises up. Therefore, warm surface water results in moist air and more rainfall.
What does the Ekman spiral describe?
The Ekman spiral is a structure of currents or winds near a horizontal boundary in which the flow direction rotates as one moves away from the boundary. It derives its name from the Swedish oceanographer Vagn Walfrid Ekman.
What is the cause of the Ekman spiral quizlet?
Due to the Coriolis effect, the surface layer is expected to drift 45 degrees to the right or left of the wind. Water at lower layers drifts to the right or left, though not as fast as the layers above it due to friction. The sum of water layer movement due to the Ekman spiral pattern.