OCE Ch 7

Of the following statements about deep-ocean currents, which is/are true?

-Deep-ocean currents are initiated by downwelling of cold, dense water near Antarctica and in the North Atlantic Ocean. -Deep-ocean currents contain water that is high in oxygen. -Deep-ocean circulation is often referred to as thermohaline flow. -The volume of water involved in the downward movement of deep-ocean currents is equal to the flow of 100 Amazon-sized rivers. -Deep-ocean currents are important regulators of global climate.

Of the following gyres, which one(s) flow in a counterclockwise direction?

-Indian Ocean Subtropical Gyre -Northern Hemisphere Subpolar Gyres -South Atlantic Subtropical Gyre -South Pacific Subtropical Gyre

Please identify the word and/or phrase that does NOT fit the pattern. A. Agulhas Current B. Benguela Current C. California Current D. Canary Current E. West Australian Current

A

Please identify the word and/or phrase that does NOT fit the pattern. A. California Current B. Canary Current C. Gulf Stream D. North Atlantic Current E. North Equatorial Current in the Atlantic Ocean

A

Please identify the word and/or phrase that does NOT fit the pattern. A. Gulf of Alaska B. Indian C. North Atlantic D. South Atlantic E. South Pacific

A

The arrangement of water masses in the southern Atlantic Ocean from the surface to the bottom is:

Antarctic Intermediate Water, North Atlantic Deep Water, Antarctic Bottom Water.

Which of the following is a western boundary current?

Brazil Current

Please identify the word and/or phrase that does NOT fit the pattern. A. thermohaline circulation B. density-driven circulation C. Antarctic Bottom Water D. Kuroshio Current E. North Atlantic Deep Water

D

Please identify the word and/or phrase that does NOT fit the pattern. A. Australian drought B. decreased fish stock in coastal Peru C. flooding rains in southeastern U.S. D. Peruvian upwelling stops E. strong trade winds

E

True or False: Deep ocean water does not travel across the equator.

False

True or False: Surface currents affect about 90% of the world's ocean water.

False

True or False: Surface or wind-driven currents move water primarily in a vertical direction in the ocean.

False

True or False: The Gulf Stream moves water away from the equator; the Benguela Current moves some of this same water back toward the equator.

False

True or False: The West Wind Drift occurs at 60°N around the Arctic Circle.

False

True or False: The densest ocean water is North Atlantic Deep Water.

False

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

Which of the following is not an eastern boundary current?

Gulf Stream

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.

Identify the mismatched pair from the choices below.

Labrador Current, Humboldt Current

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

North Atlantic Deep Water

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

Southern Ocean

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.

True or False: Deep ocean currents often move cold, dense water away from the poles.

True

True or False: Deep ocean water can be enriched in oxygen when it is mixed with surface water.

True

True or False: Deep ocean water masses have characteristic temperatures and salinities.

True

True or False: Downwelling may be the result of winds blowing parallel to a coastline or the convergence of surface currents.

True

True or False: Dynamic topography can be used to determine current direction and velocity.

True

True or False: In the northern hemisphere, Ekman transport pushes surface water to the right of the wind direction.

True

True or False: Monsoons are seasonal pressure systems that develop at lower latitudes over continents, which cause changes in seasonal winds and precipitation patterns.

True

True or False: Western boundary currents such as the Gulf Stream transport warm water from the tropics towards higher latitudes.

True

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

During a strong El Niño event, the news media might be expected to cover __________.

a tropical cyclone in Hawaii or Tahiti

Warm ocean currents ___.

are warmer than the surrounding water

When a meander from the Gulf Stream pinches off and isolates a body of water within the North Atlantic gyre, the body of water is called a:

cold core ring

California Current

cold current, northern hemisphere, temperate latitudes

Canary Current

cold current, northern hemisphere, temperate latitudes

West Wind Drift

cold current, polar latitudes, southern hemisphere

Benguela Current

cold current, southern hemisphere, temperate latitudes

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

denser

Deep ocean currents are driven primarily by ________ .

density differences

The worldwide effects of El Niño include all the following except :

drought in the U.S. Gulf coastal states.

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.

Cool ocean currents ___.

generally flow from high latitudes towards the equator

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

gyre

upwelling

movement of water from the bottom to the top of the water column

Kuroshio Current

northern hemisphere, temperate latitudes, warm current

The subtropical gyres ___.

play a large role in climate

An indirect method of measuring ocean current is the use of __________.

radar altimeters

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

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

subtropical convergences.

Thermohaline circulation in the ocean is driven primarily by differences in __________ and __________ among water masses.

temperature; salinity

All are true of the Antarctic Circumpolar Current except :

the Antarctic Circumpolar Current contributes to the development of Antarctic bottom water in the Weddell Sea.

Under which conditions are droughts and wildfires common in Australia?

under El Nino conditions

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

western boundary currents

Upwelling occurs in all the following locations except :

where deep-ocean currents are formed.

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

wind; the Coriolis effect and land

The West Wind Drift (Antarctic Circumpolar Current) is a part of which of the following subtropical gyres?

-Indian Ocean Subtropical Gyre -South Atlantic Subtropical Gyre -South Pacific Subtropical Gyre

Of the following surface currents, which one(s) flow generally from west to east?

-North Pacific Current -Equatorial Counter Current -West Wind Drift

Of the following locations, where would upwelling be expected to occur?

-Of the following locations, where would upwelling be expected to occur? -Where there is a sharp bend in a coastline -Where there is a shallowly submerged sea floor obstruction, such as a tablemount -In areas of diverging surface currents, such as along the equator -In areas of offshore winds

Of the following surface currents, which one(s) flow from south to north?

-Peru Current -Kuroshio Current -the Gulf Stream

Surface ocean currents ___.

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

Compared to an eastern boundary current in a gyre, which of the following statements is true for a western boundary current?

-narrower current -deeper current -increased current velocity -warmer water

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

45° to the right of wind direction

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

Ekman transport

net water movement to the left or right of the direction of the wind

Gulf Stream

northern hemisphere, temperate latitudes, warm 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

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.