OCE1001 CH 7

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

Gulf Stream

Deep ocean currents often move cold, dense water away from the poles.

True

Deep ocean water can be enriched in oxygen when it is mixed with surface water.

True

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

Upwelling

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

downwelling

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

Ekman Transport

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

An indirect method of measuring ocean current is the use of

radar altimeters

The Ekman spiral is caused by:

the wind and the Coriolis effect.

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

wind; the Coriolis effect and land

The Gulf Stream transports warm water into the

North Atlantic

Identify the mismatched pair from the choices below. Identify the mismatched pair from the choices below. A) Kuroshio Current, California Current B) Labrador Current, Humboldt Current C) Brazil Current, Benguela Current D) Agulhas Current, West Australia Current E) Canary Current, Gulf Stream

Labrador Current, Humboldt current

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

North Atlantic Deep Water

The densest ocean water is North Atlantic Deep Water.

False

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

1. Indian Ocean Subtropical Gyre 2. South Atlantic Subtropical Gyre 3. South Pacific Subtropical Gyre

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern. A. Agulhas Current B. Benguela Current C. California Current D. Canary Current E. West Australian Current

A. Agulhuas Current

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option that does not fit the pattern. A. California Current B. Canary Current C. Gulf Stream D. North Atlantic Current E. North Equatorial Current

A. California Current

Of the following currents, which ones are parts of the South Atlantic Subtropical Gyre? A) South Equatorial Current B) West Wind Drift C) Brazil Current D) West Australian Current E) Benguela Current F) Agulhas Current

C) Brazil Current E) Benguela Current B) West Wind Drift A) South Equatorial Current

Which of the following statements is true of surface ocean currents? A) Surface currents occur within and below the pycnocline. B) Surface currents transport warm water toward the equator. C) Surface currents form circular patterns in the major ocean basins called "gyres." D) Surface currents concentrate warm water in the center of the gyre at mid latitudes. E) Surface currents transport cold water toward the poles.

C) surface currents form circular patterns in the major ocean basins called "gyres"

Compared to western boundary currents, eastern boundary currents are:

broad and slow.

Of the following gyres, which one(s) flow in a counterclockwise direction? A) South Pacific Subtropical Gyre B) Indian Ocean Subtropical Gyre C) North Atlantic Subtropical Gyre D) Northern Hemisphere Subpolar Gyres E) North Pacific Subtropical Gyre F) South Atlantic Subtropical Gyre

D) Northern Hemisphere Subpolar Gyres A) South Pacific Subtropical Gyre F) South Atlantic Subtropical Gyre B) Indian Ocean Subtropical Gyre

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Choose the one option 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. Kuroshio Current

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

E) Ekman transport is to the right of the wind direction in the Northern hemisphere the Northern Hemisphere. F) Within the Ekman spiral, deeper water can move in a direction exactly opposite of the wind direction. A) Connecting the arrows of water movement from the surface into deeper waters shows the spiral pattern. C) The two factors that affect the Ekman spiral are the wind direction and the Coriolis effect. B) Because of the Coriolis effect, surface waters move at an angle to the wind direction.

Which of the following is not an eastern boundary current? Which of the following is not an eastern boundary current? A) W. Australian Current B) Canary Current C) California Current D) Peru Current E) Gulf Stream

E) Gulf Stream

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

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

An eastern boundary current is generally narrow and shift

False

Deep ocean water does not travel across the equator.

False

The West Wind Drift occurs at 60°N around the Arctic Circle.

False

Cool ocean currents

generally flow from high latitudes towards the equator

Of the following statements about subtropical gyres, which is/are true

1. Globally, there are five subtropical gyres. 2. The rotation of each subtropical gyre causes a "hill" of water to pile up within it. 3. The western boundary current of all subtropical gyres is intensified (it is fast, narrow, and deep). 4. There are four main surface currents in each subtropical gyre. 5. The centers of all subtropical gyres are associated with high atmospheric pressure.

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

1. Increased abundance of hurricanes in the eastern Pacific Ocean 2. Higher sea levels in the eastern Pacific Ocean associated with warmer water 3. Increase in sea surface temperatures and destruction of coral reefs in the eastern Pacific Ocean

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

1. Where there is a shallowly submerged sea floor obstruction, such as a table mount 2. In areas of diverging surface currents, such as along the equator 3. Where there is a sharp bend in a coastline 4. In areas of offshore winds

Western intensification causes:

1. equatorial countercurrents. 2. a steeper slope of surface water in the western section of the gyre as compare to the eastern section of the gyre. 3. very swift western boundary currents. 4. the center of the gyre to be shift to the west. 5.All of the above statements are the result of westward intensification.

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

1.Equatorial Counter Current 2. West Wind Drift 3. North Pacific Current

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

45° to the right of wind direction

To produce a surface current of 1.6 knots in the opean ocean, a steady wind of ____ knots would be required

80 (1.6 is 2% of 80)

The arrangement of water masses in the southern Atlantic Ocean from the surface to the bottom is: A) Antarctic Intermediate Water, North Atlantic Deep Water, Antarctic Bottom Water. B) North Atlantic Deep Water, Antarctic Bottom Water, Antarctic Intermediate Water. C) Antarctic Intermediate Water, Antarctic Bottom Water, North Atlantic Deep Water. D) Antarctic Bottom Water, Antarctic Intermediate Water, North Atlantic Deep Water. E) North Atlantic Deep Water, Antarctic Intermediate Water, Antarctic Bottom Water.

A) Antartic Intermediate Water, North Atlantic Deep Water, Antarctic Bottom Water

Which of the following is a western boundary current? Which of the following is a western boundary current? A) Brazil Current B) Canary Current C) Peru Current D) Benguela Current E) California Current

A) Brazil Current

Of the following surface currents, which ones flow from south to north A) North Pacific Current B) Kuroshio Current C) Peru Current D) Canary Current E) the Gulf Stream F) Brazil Current

B) Kuroshio Current E) The Gulf Stream C) Peru Current

Surface ocean currents ___. A) transfer large amounts of heat from the high latitudes toward the equator B) form large rotating gyres in the major ocean basins C) are driven by winds D) are influenced by Coriolis effect

B) form large rotating gyres in the major ocean basinss C) are driven by winds D) are influenced by the Coriolis effect

Which type of current flow moves in a circular path around a subtropical convergence, reflecting Ekman transport, gravity, and the Coriolis effect? Which type of current flow moves in a circular path around a subtropical convergence, reflecting Ekman transport, gravity, and the Coriolis effect? A) thermohaline circulation B) density-driven circulation C) Langmuir circulation D) geostrophic circulation E) counter-current circulation

D) geostrophic circulation

Geostrophic circulation within a gyre driven by: Geostrophic circulation within a gyre driven by: A) salinity and gravity. B) temperature and pressure. C) the wind and pressure. D) gravity and the Coriolis effect. E) density and the wind

D) gravity and the Coriolis effect

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

Surface Currents affect about 90% of the world's ocean water

False

Surface ocean currents are vertical currents in the water column that are density-driven.

False

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

False

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

False

Thermohaline circulation is wind-driven

False

Thermohaline circulation is driven by:

density differences

Indian Ocean currents that are generated by seasonal changes in weather patterns are the __________ and __________ Currents.

Somali/Southwest Monsoon

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

A Doppler flow meter is a scientific measurement used to measure current flow rates

True

Deep ocean water masses have characteristic temperatures and salinities.

True

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

True

Dynamic topography can be used to determine current direction and velocity.

True

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

True

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

True

The circular movement of surface water currents driven by the major wind belts are called gyres.

True

The main current in antartic waters is the Antartic Circumpolar Current, also called the west wind drift

True

The subtropical gyres exhibit geostrophic flow, related to pressure gradients, friction and the Coriolis effect

True

Western boundary currents such as the Gulf Stream transport warm water from the tropics towards higher latitudes

True

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

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

Under which conditions are droughts and wildfires common in Australia?

Under El Nino conditions

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

West Wind Drift

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

A thermocline is

a steep temperature gradient in the ocean that seperates deeper colder water from warmer upper water

During a strong El Nino event, the news media might be expected to cover

a tropical cyclone in Hawaii or Tahiti

Warm ocean currents

are warmer than the surrounding waters

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

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

Downwelling can result from ______

converging surface currents

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

denser

Deep ocean currents are driven primarily by ____ and modified by _____

density differences; differences in salinity and temperature

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

drought in the U.S. Gulf coastal states.

Equatorial currents that are apart 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 Nino conditions?

eastward

Ocean frontal systems that spin off from currents such as the gulf stream, akin to atmospheric storms are known as

eddies

During winter months, monsoon winds over the Indian Ocean:

flow from land to sea and are dry.

Deep-water circulation brings dense, cold, oxygen rich water from the surface to the deep ocean because of:

greater dissolution of oxygen in colder water than warmer water

One of the worlds most powerful currents, located off the east coast of the US is the

gulf stream

A large system of rotating ocean currrents, usually driven by the major wind belts is called a

gyre

Compared to Antarctic Bottom Water, North Atlantic Deep Water is:

lower in oxygen.

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

lowering of the south pacific ocean temp from normal conditions

Flucuations in the flow of the Gulf Stream result in curving loops of water known was

meanders

Gulf Stream

northern hemisphere, temperate latitudes, warm current

Kuroshio Current

northern hemisphere, temperate latitudes, warm current

The subtropical gyres ____

play a large role in climate

Deep Ocean Currents

result from changes in water density (due to temp 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.

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.

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

upwelling

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

warmer water narrower current deeper current increased current velocity All of the above statements are true of western boundary currents.

geostrophic current

water flow driven by gravity and modified by the Coriolis force

Warm core rings and cold core rings are associated with

western boundary currents

Strong upwelling occurs in all of the following except:

where deep ocean water currents are formed.