OCE 1001 Ch 7

Western intensification is ________.

"channel"

Which of the following are western boundary currents? (3)

-Brazil Current -Kuroshio Current -East Australia Current

Which of the following statements is/are true regarding surface ocean currents? (2)

-Gyres in the Southern Hemisphere rotate counterclockwise. -Cold currents flow at high latitudes or from higher latitudes toward the equator.

Of the following conditions, which is/are related to strong El Niño events? (3)

-Increase in sea surface temperatures -Increased abundance of hurricanes -Higher sea levels

Of the following surface currents, which one(s) transport large volumes of warm water to higher latitudes? (4)

-Kuroshio Current -North Pacific Current -the Gulf Stream -Brazil Current

On a west coast in the Northern Hemisphere, what happens to surface waters when winds blow from the north? (2)

-Surface waters move offshore. -Upwelling occurs.

On a west coast in the Northern Hemisphere, what happens to surface waters when winds blow from the south? (2)

-Surface waters move onshore. -Downwelling occurs.

Of the following statements about subtropical gyres, which is/are true? (5)

-The western -The rotation -Globally -There are four -The centers

Which factor(s) below drive(s) and shape(s) the pattern of surface ocean currents? (3)

-density -wind -Coriolis effect

Why does the west coast of South Africa have high biological productivity? (2)

-lots of coastal upwelling -high concentrations of nutrients in the surface water

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

2

Ekman transport is an average path of motion that, under ideal conditions, is at ________ to the wind's direction.

90 degrees

East Coast of the United States:

A: cold water B: cold water rings C: warm water D: warm water rings

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

Accidental spills from container ships

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

Antarctic Circumpolar

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

T/F? Subtropical gyres flow counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.

False

T/F? Vertical mixing of surface and deep seawater takes place in the low latitudes.

False

Which of the following statements about El Niño events is false?

Fishing along Peru and Ecuador is much better.

Gulf Stream Current is next to __________ Benguela Current is next to __________ Peru Current is next to __________

Florida Africa South America (left)

El Nino Conditions:

From left to right High atmospheric pressure Walker Circulation Cell (reversed direction) Pacific Warm Pool Low atmospheric pressure Thermocline

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

Subpolar gyre is next to __________ Canary Current is next to __________ California Current is next to __________

Iceland Europe California

Water masses in Atlantic Ocean:

In order from left to right: Upwelling Seasonally warm water (top) North Atlantic deep water (bottom) Thermocline and pycnocline Warmest water (top) Antarctic Bottom Water (bottom) Antarctic Intermediate Water

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.

The Gulf Stream transports warm water into the __________.

North Atlantic

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

Somali Current

Subtropical gyre is next to __________ Brazil Current is next to __________ Antarctic Circumpolar Current (West Wind Drift) is next to __________

South America and Africa South America (right) Antarctica

The deepest and densest water mass in the world ocean is formed in the __________________.

Southern Ocean

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

Subtropical convergence

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.

T/F? The East Australian Current is the western boundary current of the South Pacific subtropical gyre.

True

Which of the following is true of surface water circulation near Antarctica?

Two circumpolar currents dominate it, one current that moves water to the east and one current that moves water to the west.

Under which conditions are droughts and wildfires common in Australia?

Under El Niño conditions

The atmospheric circulation cell located in the equatorial South Pacific and created by the movement of air between high- and low-pressure regions is called the __________.

Walker Cell

What is one of the first indications that an El Niño event may be occurring?

Warm water originating near Australia migrates toward South America.

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

West Wind Drift

Which of the following currents goes all the way around the world without being interrupted by land?

West Wind Drift

The observation that one subtropical boundary current is faster, narrower, and deeper than its counterparts is an example of which of the following?

Western intensification

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

Compared to western boundary currents, eastern boundary currents are:

broad and slow

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 Peru Current is a _______ current that flows _______.

cold; north

The California Current is a ________ current that flows ________.

cold; south

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 flow is a term that describes ________.

deep-ocean current movement

Deep ocean currents are driven primarily by ________ .

density differences

Thermohaline circulation is driven by:

density differences.

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

doppler flow meters

Converging surface waters are areas of ________ and ________ productivity.

downwelling; low

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

eastward

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

eddies

Which of the following two factors cause geostrophic circulation within a gyre?

gravity and the Coriolis effect

Deep-water circulation brings oxygen from the surface to the deep ocean because of:

greater dissolution of oxygen in colder water than warmer water.

A geostrophic current is one that (ideally) flows _______.

in a circular path around the central "hill" of a gyre

Deep-water currents move ________ volumes of water and are much ________ than surface currents.

larger; slower

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

Warm currents flowing ________ on the ________ sides of continents produce warm, humid conditions.

poleward; eastern

In subtropical gyres, western boundary currents have all of the following characteristics except being __________.

relatively wide

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

Sources of deep water in the ocean include all of the following except:

subtropical convergences

The ocean's deep water is initially formed at the _________ and in _________ regions.

surface; subpolar

Which of the following currents does not belong with the others as part of the same gyre?

the Agulhas Current

Which of the following is an example of a western boundary current of a subtropical gyre?

the Kuroshio Current

In comparison to wind energy, ocean currents can generate more clean, renewable energy because __________.

the density of water is greater than that of air

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

Cold currents flowing ________ on the ________ sides of continents produce arid conditions.

toward the equator; western

Equatorial currents are driven by the:

trade winds

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

upwelling

Diverging surface waters are areas of ________ and ________ productivity.

upwelling; high

The East Australian Current is a ________ current that flows ________.

warm; south

Surface ocean currents are driven primarily by ________ and modified by ________.

wind; the Coriolis effect and land