What Causes Upwelling To Occur?

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.

Why does upwelling occur quizlet?

why does upwelling/downwelling happen? occurs where Ekman transport moves surface waters away from the coast; surface waters are replaced by water that wells up from below. … Winds blowing from the north cause upwelling along the continents’ eastern coasts in the Southern Hemisphere.

What causes upwelling in lakes?

Occurs when dense cool nutrient rich water from the bottom of the water column offshore replaces the nutrient depleted surface water in the nearshore. Wind blows across the lake. As water moves away from the shore, the lost water is replaced by upwelling of deep waters. …

Does upwelling occur in lakes?

This wind direction often causes upwelling along the eastern shore of the lake. Upwelling is a process by which offshore winds push surface water away from shore, allowing cold lake water to rise up to the surface from beneath.

What are 3 areas of upwelling in the world?

Worldwide, there are five major coastal currents associated with upwelling areas: the Canary Current (off Northwest Africa), the Benguela Current (off southern Africa), the California Current (off California and Oregon), the Humboldt Current (off Peru and Chile), and the Somali Current (off Somalia and Oman).

What makes upwelling and downwelling occur what biological effects do they have?

Upwelling waters may originate below the pycnocline and are therefore colder than the surface waters they replace. … Downwelling reduces biological productivity and transports heat, dissolved materials, and surface waters rich in dissolved oxygen to greater depths.

Which event typically causes upwelling quizlet?

Which event typically causes upwelling? Wind blows warm water away from the shore.

Is there upwelling or downwelling occurring in the center of a subtropical gyre?

The centres of subtropical gyres are shifted to the west. This westward intensification of ocean currents was explained by the American meteorologist and oceanographer Henry M. … Associated with these currents is coastal upwelling that results from offshore Ekman transport.

What is an example of upwelling?

Upwelling occurs in the open ocean and along coastlines. … 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.

Is upwelling good or bad?

Upwelling occurs in the late spring and summer when wind drives cooler, dense, and nutrient-rich water toward the ocean surface, replacing the warmer surface water. … “On the other hand,” he said, “it could be really bad” if it raises turbulence, disrupts feeding, worsens ocean acidification, and lowers oxygen levels.

What is the positive effect of upwelling?

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. Therefore, good fishing grounds typically are found where upwelling is common.

What would happen if upwelling stopped?

What might happen to fisheries if upwelling stopped? Fish population would die or lessen. How is the direction of a surface current affected? … It carries warm water to colder water creating a convection current.

How does upwelling affect weather?

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 are two specific regions where significant upwelling occurs?

Most major upwelling regions are found along the west coasts of continents, such as off California, Peru, Namibia and South Africa. Large-scale upwelling off the west coast of Australia is suppressed due to the poleward-flowing Leeuwin Current.

Why is downwelling important?

Downwelling also allows for deep ocean oxygenation to occur because these waters are able to bring dissolved oxygen down from the surface to help facilitate aerobic respiration in organisms throughout the water column. … In the most extreme cases, a lack of downwelling could possibly lead to mass extinction.

Which event may occur when salinity increases?

Explanation: When salinity of water increases then due to the mass of the dissolved amount of salt the mass of the total solution increases.

What causes downwelling quizlet?

What does downwelling cause? Causes water to be forced down. … Surface water is transported off-shore and replaced by deeper water, that moves inshore and is upwelled. Reverse occurs when the wind is oriented in the opposite direction.

Why is upwelling and downwelling important?

Upwelling and downwelling describe mass movements of the ocean, which affect both surface and deep currents. These movements are essential in stirring the ocean, delivering oxygen to depth, distributing heat, and bringing nutrients to the surface.

How can upwelling affect the nutrient and oxygen?

How can upwelling affect the nutrient and oxygen content of ocean water around coastlines? It brings cold, nutrient-rich water to the ocean surface. … The oxygen level of a lake suddenly starts decreasing. A biologist believes that photosynthetic organisms in the community have become less efficient at producing oxygen.

How does Ekman cause downwelling?

As wind blows along a coastline, Ekman transport moves the surface layer in a direction 90o to the wind. … In any coastal upwelling location, if the winds reverse, surface water moves towards the shore and downwelling is the result.

How does downwelling happen?

Downwelling occurs when the water on the surface of the sea becomes denser than the water beneath it and so it sinks. Seawater gets denser when it gets colder or saltier.

Does El Nino cause upwelling?

El Niño also has a strong effect on marine life off the Pacific coast. During normal conditions, upwelling brings water from the depths to the surface; this water is cold and nutrient rich. During El Niño, upwelling weakens or stops altogether.


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