Oceanography Ch. 7

In which direction does the surface current move in relation to the wind in the Southern Hemisphere?

45 degrees to the left

To produce a surface current of 1.6 knots in the open ocean, a steady wind of _____ knots would be required.

80

Which of the following is the only current that completely circumscribes Earth?

Antarctic Circumpolar

The Benguela Current is an example of which of the following types of currents?

Eastern Boundary Current

The California Current is an example of which of the following types of currents?

Eastern Boundary Current

Coastal winds can cause upwelling or downwelling due to which of the following?

Ekman transport

Which current that flows along the equator is driven by a difference in sea level caused by ocean circulation patterns?

Equatorial Countercurrent in the Pacific Ocean

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

Gulf Stream

Which of the following currents is responsible for Peru becoming the largest producer of fish, from the sea, in the world?

Humboldt Current

Of the following gyres, which one(s) flow in a counterclockwise direction? Choose all that apply.

Indian Ocean, South Pacific, Northern Hemisphere, and South Atlantic (Subtropical Gyre's)

Of the following surface currents, which one(s) transport large volumes of warm water to higher latitudes? Choose all that apply.

Kuroshio Current Brazil Current the Gulf Stream

The Gulf Stream transports warm water into the __________.

North Atlantic

Which of the following methods are used to measure ocean surface currents indirectly?

Pressure gradients

Which of the following Atlantic Subtropical gyre boundary currents is split into two by a large landmass?

South Equatorial Current

The observation of a hill of water within all subtropical gyres is an example of which of the following?

Subtropical convergence

About what percent of the wind's energy is transferred to the ocean surface?

Two

The Brazil Current is an example of which of the following types of currents?

Western Boundary Current

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

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

The thermocline is _________________.

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

Surface ocean currents ___.

are influenced by Coriolis effect; form large rotating gyres in the major ocean basins; are driven by winds

Warm ocean currents ___.

are warmer than the surrounding water

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

Downwelling can result from __________.

converging surface currents

An increase in seawater density can be caused by a ________ in temperature or a/an ________ in salinity.

decrease; increase

Thermohaline circulation is driven by:

density differences.

Converging surface waters are areas of ________ and ________ productivity.

downwelling; low

Equatorial currents that are part of the subtropical gyres flow ___. Equatorial counter currents between the gyres flow ___ .

east to west; west to east

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

eastward

During winter months, monsoon winds over the Indian Ocean:

flow from land to sea and are dry.

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

Ocean surface currents transfer about ________ of the total amount of heat from the tropics to the poles.

one-third

The El Niño Southern Oscillation can best be described as:

the relationship between sea surface temperature and changing atmospheric pressure.

What is the Southern Oscillation?

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

Deep ocean current movement is also known as __________.

thermohaline flow

In the southern hemisphere, the direction of Ekman transport is always:

to the left of the wind direction.

Equatorial currents are driven by the:

trade winds.

Under which conditions are droughts and wildfires common in Australia?

under El Niño conditions

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

western boundary currents

What factor(s) drive(s) Ekman transport?

wind; Coriolis effect

The observation that ships and icebergs in the southern hemisphere float to the left of the wind direction is an example of which of the following?

Ekman transport

Which of the following methods are used to measure deep ocean currents directly?

Free-drifting Argo floats

Which ocean current is the strongest and fastest ocean current in the world?

Gulf Stream

Which of the following currents contributes to the South Eastern United States being humid?

Gulf Stream

Why is Antarctic Bottom Water so dense?

It is cold and salty.

What is the Walker Circulation Cell?

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

Which of the following methods are used to measure ocean surface currents directly?

Radio-transmitting float bottles; Accidental spills from container ships

Between summer and winter, which of the following currents reverses its flow direction?

Somali Current

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

The eastern coast of Australia would be experiencing unusually dry weather.

The Kuroshio (Japan) Current is an example of which of the following types of currents?

Western Boundary Current

Western intensification causes:

a large volume of water to flow within western boundary currents; very swift western boundary currents; the center of the gyre to be shift to the west; a steeper slope of surface water in the western section of the gyre as compared to the eastern section of the gyre

Which force(s) drive(s) water circulation in the deep ocean?

differences in water density, temperature, and salinity

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

eddies

Cool ocean currents ___.

generally flow from high latitudes towards the equator

Which two factors cause geostrophic circulation within a gyre?

gravity and the Coriolis effect.

Which process causes downwelling off the coast of Antarctica?

ice formation

The subtropical gyres ___.

play a large role in climate

Deep ocean currents ___.

result from changes in water density (due to temperature and salt content)

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

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

Coastal upwelling along the coast of Chile is a result of winds from the ________ turning towards the ________ due to Ekman transport.

south; left

The Ekman spiral is caused by:

the wind and the Coriolis effect.

Surface waters are pushed away from land and replaced by nutrient-rich bottom water through:

upwelling.