Chapter 7 Practice Questions

The actual movement of surface water due to Ekman transport in the Northern Hemisphere is about _______.

45 degrees to the right of the wind direction

One of the world's most powerful currents, located off the east coast of the United Sates, is the _______.

Gulf Stream

The current in the northwestern part of the North Atlantic Subtropical Gyre that transports warm water toward the North Atlantic is called the _______.

Gulf Stream

The Gulf Stream transports warm water into the _______.

North Atlantic

A deep and powerful southward subsurface current that flows under the Gulf Stream in the North Atlantic is the _______.

North Atlantic Deep Water

Part complete Name the main currents that exist within each subtropical gyre in the North Pacific and in the North Atlantic. Identify which of these currents are an Eastern Boundary Current or a Western Boundary Current. For the North Pacific, identify which of these currents are associated with equatorial or coastal upwelling.

The North Atlantic subtropical gyre consists of the North Equitorial Current, Antilles Current, Caribbean Current, and the Florida Current. Of these currents, the Antilles Current and the Florida Current are Western Boundary Currents. The Caribbean Currrent is an Eastern Boundary Current. The North Pacific Subtropical Gyre consistes of the North Pacific Current, the California Current, the Kuroshio Current, and the North Equitorial Current. The Eastern Boundary Current is the California Current. The Western Boundary Current is the Kuroshiro Current, this current is also assosiated with coastal upwelling.

The largest of the great ocean surface currents is the _______.

West Wind Drift

Consider the global thermohaline circulation. What drives the circulation? Why does water sink at the North and South Poles and rise at the lower latitudes of the Pacific and Indian Oceans?

What drives thermohaline circulation are changes in seawater density due to salinity or temperature. Water sinks at the North and South Poles because water temperature is decreases causing the seawater be become more dense, and seaice forms increasig the denisty of the seawater again, in turn causing the water to sink. Water rises at lower latitudes because the temperature increases at lower latitudes decreasing the waters ability to dissolve matierials, causing the sea water to become less dense, in turn causing the water to rise.

The themocline is _______.

a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water

Of the following statements about subtropical gyres, which is/are true? a. Globally, there are 5 subtropical gyres b. The centers of all subtropical gyres are associated with high atmosphereic pressure c. The rotation of eath subtropical gyre causes a "hill" of water to pile up within it d. There are four main surface currents in each subtropical gyre e. The western boundary current of all subtropical gyres is intensified (it is fast, narrow, and deep) f. Subtropical gyres flow in the same direction in both hemispheres

a, b, c, d, e

Of the following statements about deep-ocean currents, which is/are true? a. Deep-ocean currents contain water that is high in oxygen. b. Deep-ocean currents are initiated by downwelling of cold, dense water near Antarctica and in the North Atlantic Ocean. c. Deep-ocean currents often travel faster than ocean surface currents. d. The volume of water involved in the downward movement of deep-ocean currents is equal to the flow of 100 Amazon-sized rivers. e. Deep-ocean circulation is often referred to as thermohaline flow. f. Deep-ocean currents are important regulators of global climate.

a, b, d, e, f

To what depth in the ocean does the Ekman spiral extend?

about 100 meters (330 feet)

When a meander from the Gulf Stream pinches off into the warm water south of the current, the eddy is called a _______.

cold-core eddy or ring

The loss of heat from the ocean surface, resulting in a lowered temperature, causes ocean water to become _______.

denser

Which direction do ocean currents in the South Pacific move under El Nino conditions?

eastward

Ocean frontal systems that spin off from currents such as the Gulf Stream, aki to atmospheric storms, are known as _______.

eddies

A large system of rotating ocean currents, usually driven by the major wind belts, is called a(n) _______.

gyre

What is the Walker Circulation Cell?

it is the path that air takes as it moces from high to low pressure, and back to high pressure, in the South Pacific under normal conditions

What is the overall effect of the stronger than normal trade winds typical of La Nina conditions

lowering of the South Pacific ocean temperature from normal conditions

Fluctuations in the flow of the Gulf Stream current result in curving loops of water known as _______.

meanders

In the Northern Hemisphere, the Ekman spiral moves layers of water to the _______ of the wind direction and Ekman transport (the overall direction of water movement) is to the _______.

right; right

Records indicate that the ocean is warming faster in the Arctic polar regions that elsewhere. If that continues, a possible consequence could be _______.

slowing of deep circulation, resulting in lower oxygen levels in deep water

Thermohaline circulation in the ocean is dricen promarily by differences in _______ and _______ among water masses.

temperature; salinity

What would you expect weather to be like on the eastern coast of Australia if the wester coast of South America were experiencing unusually warm, wet weather?

the eastern coast of Australia would be experiencing unusually dry weather

What is Southern Oscillation?

the swapping of high and low pressure zones in the South Pacific under El Nino conditions

Under which conditions are droughts and wildfires commong Australia?

under El Nino conditions

Warm core rings and cold core rings are associated with _______.

western boundary currents

Why does upwelling occur along the west coast of South America Under normal conditions?

winds moving westard in the South Pacific drive ocean currents toward the west; deep water rises to replace water driven westward

Part complete Of the following statements about Ekman spiral and Ekman transport, which is/are true? a. Because of the Coriolis effect, surface waters move at an angle to the wind direction. b. Connecting the arrows of water movement from the surface into deeper waters shows the spiral pattern. c. Within the Ekman spiral, deeper water can move in a direction exactly opposite of the wind direction. d. Ekman transport is to the right of the wind direction in the Northern Hemisphere. e. The two factors that affect the Ekman spiral are the wind direction and the Coriolis effect. f. Ekman transport is the same thing as thermohaline flow.

a, b, c, d, e