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.