Patterns of Circulation in the Ocean

Patterns of Circulation in the Ocean

Multiple Choice

The densest water in the ocean is known as the Antarctic Bottom Water. It is formed along the Antarctic ice shelves where water freezes on the ocean's surface. The Antarctic Bottom Water plays a big role in the global circulation of ocean waters around the world. This dense water is carried along the ocean floor, delivering oxygen and nutrients to the deepest parts of oceans. Which of these conditions describes the Antarctic Bottom Water?

• cold and salty

• cold and fresh

• warm and salty

• warm and fresh

Antarctic Bottom Water is dense, cold, and salty. The Antarctic Bottom Water forms along the Antarctic ice shelves where water freezes on the ocean surface. The ice contains only fresh water, leaving the salts in the water. This causes the ocean water to become even saltier. Cold and salty water is dense, causing it to sink and flow along the ocean floor as a deep current. When the ocean surface water freezes into ice shelves as cold water sinks to the ocean floor, warmer water rises to the top of the ocean.

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​Explanation

Draw

The densest water in the ocean is known as the Antarctic Bottom Water. It is formed along the Antarctic ice shelves where water freezes on the ocean's surface. The Antarctic Bottom Water plays a big role in the global circulation of ocean waters around the world. This dense water is carried along the ocean floor, delivering oxygen and nutrients to the deepest parts of oceans. Salia is making a model of the Antarctic Bottom Water. She mixes different amounts of salt into water samples. The water is all the same temperature. Graph Salia’s data on the line graph. Predict the density of a 50-mL sample of water with 5 grams of salt added by placing a point on the graph.

Following the pattern of Salia’s model, the 5 grams of salt should result in a density of 1.1 g/mL. The density increases 0.1 g/mL for each 5 grams of salt added to the sample. The Antarctic Bottom Water is represented by the densest layer in Salia’s model.

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​Explanation

Open Ended

The densest water in the ocean is known as the Antarctic Bottom Water. It is formed along the Antarctic ice shelves where water freezes on the ocean's surface. The Antarctic Bottom Water plays a big role in the global circulation of ocean waters around the world. This dense water is carried along the ocean floor, delivering oxygen and nutrients to the deepest parts of oceans. Scientists have evidence that the Antarctic Bottom Water is becoming fresher and warmer. What are two changes that could happen as a result of this?

Cold, salty water is dense, which causes it to sink and deliver nutrients and oxygen to the deepest parts of the ocean. When water becomes fresher and warmer, it becomes less dense. If the water is less dense, it will not sink as deep, and organisms living in the deep ocean might not get the oxygen they need to survive. They might die.

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​Sample Answer

​Explanation

​When water has less salt and/or becomes warmer, it will be less dense and rise. If the ocean water is less dense, it will not sink as deep. The organisms that live at the bottom of the ocean depend on the dense water providing oxygen and nutrients for survival.

Multiple Choice

Mario is making a computer model so he can study the transport of deep currents and surface currents in the ocean. Does this description match deep currents or surface currents?

movement of ocean water caused by wind

• deep currents

• surface currents

Multiple Choice

Mario is making a computer model so he can study the transport of deep currents and surface currents in the ocean. Does this description match deep currents or surface currents?

movement of cold ocean water

• deep currents

• surface currents

Multiple Choice

Mario is making a computer model so he can study the transport of deep currents and surface currents in the ocean. Does this description match deep currents or surface currents?

movement of ocean water that cause La Nina events

• deep currents

• surface currents

Multiple Choice

Mario is making a computer model so he can study the transport of deep currents and surface currents in the ocean. Does this description match deep currents or surface currents?

movement of ocean water caused by differences in density

• deep currents

• surface currents

Deep currents are the movement of cold salty ocean water and the movement of ocean water caused by difference in density. As water gets colder and saltier, it gets denser and sinks. Surface currents are the movements of ocean water caused by wind and the movement of ocean water that cause La Niña events. Global winds affect the transport of all ocean water at the surface. When stronger winds blow above the Pacific Ocean, they cause temperature changes in the ocean water that affect weather all over the world during a La Niña event.

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Explanation

Multiple Choice

El Niño and La Niña events cause changes in weather conditions. For example, they can cause increased rainfall or snowfall. These climate events affect the weather in areas around the world for a long time. What causes the pattern of ocean currents to change during La Niña and El Niño events?

• salinity

• wind

• density

• temperature

The pattern of ocean currents during El Niño and La Niña events is caused by changes in the pattern of wind. The wind causes surface currents to move in specific directions. If you look at a map of ocean currents and at a global wind map, you will notice that the wind and ocean currents follow the same paths around the globe. The pattern of ocean currents is not caused by changes in salinity, temperature, or density. In contrast, changes in salinity, temperature, and density can be caused by changes in the pattern of ocean currents.

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Explanation

Multiple Choice

Miami is located on the east coast of Florida. A warm ocean current called the Gulf Stream is located in the Atlantic Ocean off the coast of Miami. Which of the following explains how the Gulf Stream affects the climate of Miami?

• warm and dry

• cool and rainy

• cool and dry

• warm and rainy

Being located near a warm current gives the location a warm and rainy climate year round. It could be warm, but not dry, since it is located on the coast. Being located near a cold current does cause cooler weather. Miami is known for its warm, humid climate.

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Explanation

Poll

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