oceanography chapter 7 salvaggio
Of the following statements about the Ekman spiral and Ekman transport, which is/are true? Choose all that apply.
- Ekman transport is to the right of the wind direction in the Northern Hemisphere. - Ekman transport can result in both upwelling and downwelling. - The Coriolis effect causes surface waters to move at an angle relative to the wind direction. - In the deeper layers of the Ekman spiral, water can move in a direction opposite of the wind direction.
Of the following locations, where would upwelling be expected to occur? Choose all that apply. -Where seamounts or table mounts are present -Where there is a sharp bend in a coastline -In areas of converging surface currents -In regions with a well developed pycnocline -In areas of diverging surface currents
- In areas of diverging surface currents - Where seamounts or tablemounts are present - where there is a sharp bend in a coastline
Of the following surface currents, which one(s) transport large volumes of warm water to higher latitudes? Choose all that apply. Brazil Current Peru Current Kuroshio Current the Gulf Stream Canary Current North Pacific Current
- Kuroshio Current - Brazil Current - the Gulf Stream
Of the following gyres, which one(s) flow in a counterclockwise direction? Choose all that apply. Northern Hemisphere Subpolar Gyres North Pacific Subtropical Gyre North Atlantic Subtropical Gyre South Atlantic Subtropical Gyre South Pacific Subtropical Gyre Indian Ocean Subtropical Gyre
- South Atlantic Subtropical Gyre - South Pacific Subtropical Gyre - Northern Hemisphere Subpolar Gyres - Indian Ocean Subtropical Gyre
Recall that global winds impact the direction of surface ocean currents. Examine the following map showing the Atlantic Ocean off the west coast of Africa. The direction of the surface current and the prevailing wind do not coincide. What can explain this discrepancy? -The Coriolis effect deflects ocean currents in the Southern Hemisphere to the left due to Earth's rotation. -The current is being pulled in a clockwise direction because the subtropical gyre is located in the Southern Hemisphere. -Because the current is located in the Southern Hemisphere, the subtropical gyre pulls the current in a counterclockwise direction. -The ocean current is being deflected to the right due to the Coriolis effect.
- The Coriolis effect deflects ocean currents in the Southern Hemisphere to the left due to Earth's rotation. - Because the current is located in the Southern Hemisphere, the subtropical gyre pulls the current in a counterclockwise direction.
Which force(s) drive(s) water circulation in the deep ocean? differences in water temperature wind differences in water salinity differences in water density differences in water pH
- differences in water density - differences in water temperature - differences in water salinity
Based on the graph, which of the following has the highest salinity? Antarctic Bottom Water (AABW) Antarctic Intermediate Water (AAIW) Mediterranean Intermediate Water (MIW) North Atlantic Central Surface Water (NACSW) North Atlantic Deep Water (NADW)
Mediterranean Intermediate Water (MIW)
The Gulf Stream transports warm water into the __________. Caribbean Sea Eastern Atlantic North Atlantic South Atlantic Gulf of Mexico
North Atlantic
The observation of a hill of water within all subtropical gyres is an example of which of the following? Western intensification Eastern intensification Geostrophic current Subtropical convergence Equatorial upwelling
Subtropical convergence
Which of the following statements is true of surface ocean currents? -Surface currents concentrate warm water in the center of the gyre at mid latitudes. -Surface currents transport cold water toward the poles. -Surface currents form circular patterns in the major ocean basins called "gyres." -Surface currents occur within and below the pycnocline. -Surface currents transport warm water toward the equator.
Surface currents form circular patterns in the major ocean basins called "gyres."
Subtropical gyres flow counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. True False
False
Which of the following statements about El Niño events is false? -Fishing along Peru and Ecuador is much better. -The trade winds stop or even reverse. -Upwelling slows or halts offshore of South America. -A low-pressure zone migrates eastward toward Peru. -There is a deeper wedge of warm water off South America.
Fishing along Peru and Ecuador is much better.
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 __________. gyros cell thermohaline cell Hadley cell Walker cell Ferrel cell
Walker cell
The Brazil Current is an example of which of the following types of currents? Eastern Boundary Current Equatorial Counter Current Northern Boundary Current Southern Boundary Current Western Boundary Current
Western Boundary Current
The Kuroshio (Japan) Current is an example of which of the following types of currents? Eastern Boundary Current Equatorial Counter Current Northern Boundary Current Southern Boundary Current Western Boundary Current
Western Boundary Current
When a meander from the Gulf Stream pinches off into the warm water south of the current, the eddy is called a __________. -cyclonic circulation -Langmuir cell -warm-core eddy or ring -cold-core eddy or ring -geostrophic circulation
cold-core eddy or ring
The Peru Current is a _______ current that flows _______. cold; south warm; east warm; north warm; south cold; east cold; north
cold; north
Why does upwelling occur along the west coast of South America under normal conditions? Winds moving northward in the South Pacific drive ocean currents toward the north; deep water rises to replace water driven northward. Winds moving eastward in the South Pacific drive ocean currents toward the east; deep water rises to replace water driven eastward. Winds moving westward in the South Pacific drive ocean currents toward the west; deep water rises to replace water driven westward. Winds moving southward in the South Pacific drive ocean currents toward the south; deep water rises to replace water driven southward.
Winds moving westward in the South Pacific drive ocean currents toward the west; deep water rises to replace water driven westward.
The subtropical gyres ___. -are only important because the currents affect ships crossing them -play a large role in climate -result from changes in water density (due to temperature and salt content) -drive the trade winds
play a large role in climate
Equatorial currents are driven by the: trade winds. westerlies. Coriolis force. Ekman transport. density.
trade winds.
About what percent of the wind's energy is transferred to the ocean surface? Five Two Fifty Ten Twenty
Two
Western intensification is ________. -found only in the northern Pacific Ocean -caused by the rotational center of a gyre being located to the west of the ocean basin's geographic center, thus causing more water to flow within a narrower "channel" -another name for the process of thermohaline flow -demonstrated by El Niño -another term for Ekman transport
caused by the rotational center of a gyre being located to the west of the ocean basin's geographic center, thus causing more water to flow within a narrower "channel"
Surface ocean currents ___. -are driven by winds -transfer large amounts of heat from the high latitudes toward the equator -form large rotating gyres in the major ocean basins -are influenced by Coriolis effect
-Are driven by winds -Form large rotating gyres in the major ocean basins -Are influenced by Coriolis effect
What factor(s) drive(s) Ekman transport? boat movement water temperature wind Coriolis effect water salinity
-Wind -Coriolis effect
In which direction does the surface current move in relation to the wind in the Southern Hemisphere? in the same direction 45 degrees to the right 45 degrees to the left 90 degrees to the left 90 degrees to the right
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. 50 40 100 80 60
80
Which of the following methods are used to measure ocean surface currents directly? Pressure gradients Doppler flow meters Accidental spills from container ships Radar altimeters Anchored buoys
Accidental spills from container ships
Western intensification causes: -very swift western boundary currents. -All the above effects are the result of western intensification.
All the above effects are the result of western intensification.
Compared to an eastern boundary current in a gyre, which of the following statements is true for a western boundary current? warmer water increased current velocity narrower current deeper current All the above statements are true of western boundary currents.
All the above statements are true of western boundary currents.
Based on the graph, which of the following has the lowest temperature? Antarctic Bottom Water (AABW) Antarctic Intermediate Water (AAIW) Mediterranean Intermediate Water (MIW) North Atlantic Central Surface Water (NACSW) North Atlantic Deep Water (NADW)
Antarctic Bottom Water (AABW)
Which of the following is the only current that completely circumscribes Earth? South Equatorial Benguela Malvinas Antarctic Circumpolar South Australian
Antarctic Circumpolar
Waters along the California coast are colder than those along the mid-Atlantic shore of the U.S. because
Coastal Upwelling
Why do the lengths of the arrows in the Ekman spiral get shorter and shorter as you move deeper into the water column? There is less water in each progressive layer. There is less light transmission with increased depth. Deeper water moves at a slower speed due to friction. The temperature gets colder with depth. The Coriolis effect weakens as depth increases.
Deeper water moves at a slower speed due to friction.
The Benguela Current is an example of which of the following types of currents? Eastern Boundary Current Equatorial Counter Current Northern Boundary Current Southern Boundary Current Western Boundary Current
Eastern Boundary Current
The California Current is an example of which of the following types of currents? Eastern Boundary Current Equatorial Counter Current Northern Boundary Current Southern Boundary Current Western Boundary Current
Eastern Boundary Current
Coastal winds can cause upwelling or downwelling due to which of the following? Eastern intensification Ekman transport Equatorial upwelling Western intensification Geostrophic current
Ekman transport
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? Equatorial upwelling Western intensification Ekman transport Eastern intensification Geostrophic current
Ekman transport
The false-color map of sea surface temperatures shown below is an example of which of the following features? Eddies Monsoons Cyclones Upwelling El Nino conditions
El Nino conditions
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 -North Equatorial Current in the North Atlantic Gyre -South Equatorial Current in the North Pacific Gyre -North Equatorial Current in the North Pacific Gyre -South Equatorial Current in the Indian Ocean Gyre
Equatorial Countercurrent in the Pacific Ocean
Which of the following methods are used to measure deep ocean currents directly? Radio transmitting float bottles Accidental spills from container ships Radar altimeters Propeller flow meters Free drifting Argo floats
Free-drifting Argo floats
One of the world's most powerful currents, located off the east coast of the United States, is the __________. Kuroshio Current Gulf Stream Canary Current North Equatorial Current North Atlantic Current
Gulf Stream
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? North Atlantic Current Gulf Stream Brazil Current North Equatorial Current California Current
Gulf Stream
Which of the following currents is responsible for Peru becoming the largest producer of fish, from the sea, in the world? Brazil Current Falkland Current Humboldt Current Canary Current Somali Current
Humboldt Current
Why is Antarctic Bottom Water so dense? It is only seasonally warmed by the sun. It warms as it approaches the equator. It is extremely fresh due to ice melt. It is under immense pressure. It is cold and salty.
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 El Niño conditions. -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. -It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Atlantic under El Niño conditions. -It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the North Pacific under normal conditions. -It is the path that air takes as it moves from high to low pressure, and back to high pressure, in the South Atlantic under normal conditions.
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.
Based on the graph, which of the following has the lowest density? Antarctic Bottom Water (AABW) Antarctic Intermediate Water (AAIW) Mediterranean Intermediate Water (MIW) North Atlantic Central Surface Water (NACSW) North Atlantic Deep Water (NADW)
North Atlantic Central Surface Water (NACSW)
Palm trees associated with the subtropics can be found at the northern tip of the British Isles in Scotland. This is due to the transfer of heat from the ___
North Atlantic Current
Which of the following methods are used to measure ocean surface currents indirectly? Free drifting Argo floats Accidental spills from container ships Pressure gradients Radio transmitting float bottles Propeller flow meters
Pressure gradients
Which of the following methods are used to measure ocean surface currents directly? Radar altimeters Doppler flow meters Pressure gradients Radio transmitting float bottles Anchored buoys
Radio-transmitting float bottles
Between summer and winter, which of the following currents reverses its flow direction? Brazil Current Falkland Current California Current Somali Current Florida Current
Somali Current
Which of the following Atlantic Subtropical gyre boundary currents is split into two by a large landmass? Brazil Current South Equatorial Current Benguela Current Canary Current North Atlantic Current
South Equatorial 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 eastern coast of Australia would be experiencing unusually warm weather. The eastern coast of Australia would be experiencing unusually cool weather. The eastern coast of Australia would be experiencing unusually wet weather.
The eastern coast of Australia would be experiencing unusually dry weather.
The thermocline is _________________. -a steep gradient in the ocean that separates deeper less salty water from saltier upper water. -a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water -a steep temperature gradient in the ocean that separates deeper warm water from colder upper water -a steep gradient in the ocean that separates deeper saltier water from less salty upper water
a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water
Warm ocean currents ___. -are warmer than 15 degrees Celsius -are warmer than the surrounding water -generally flow from high latitudes towards the equator -generally flow along the west coasts of continents
are warmer than the surrounding water
Downwelling can result from __________. Ekman transport away from a coast strong offshore winds diverging surface currents an ocean current flowing over submerged banks or seamounts converging surface currents
converging surface currents
An increase in seawater density can be caused by a ________ in temperature or a/an ________ in salinity. increase; decrease decrease; decrease decrease; increase increase; increase
decrease; increase
Thermohaline circulation is driven by: longitude. density differences. latitude. the Coriolis effect. wind.
density differences.
Converging surface waters are areas of ________ and ________ productivity. upwelling; high downwelling; low upwelling; low downwelling; high
downwelling; low
Equatorial currents that are part of the subtropical gyres flow ___. Equatorial counter currents between the gyres flow ___ . west to east; west to east east to west; east to west east to west; west to east west to east; east to west
east to west; west to east
Which direction do ocean currents in the South Pacific move under El Niño conditions? northward westward southward eastward
eastward
Ocean frontal systems that spin off from currents such as the Gulf Stream, akin to atmospheric storms, are known as __________. eddies meanders geostrophic flow
eddies
During winter months, monsoon winds over the Indian Ocean: the direction of airflow is unchanged but precipitation increases. flow from land to sea and are wet. flow from sea to land and are wet. flow from sea to land and are dry. flow from land to sea and are dry.
flow from land to sea and are dry.
Cool ocean currents ___. are still warmer than the surrounding water are cooler than 15 degrees C generally flow along the east coasts of continents generally flow from high latitudes towards the equator
generally flow from high latitudes towards the equator
Which of the following two factors cause geostrophic circulation within a gyre? salinity and gravity. gravity and the Coriolis effect. temperature and pressure. the wind and pressure. density and the wind.
gravity and the Coriolis effect.
Freezing seawater at _____ leads to increases in salinity and density
high latitudes
Which process causes downwelling off the coast of Antarctica? icebergs sinking seasonal warming ice formation mixing within the pycnocline ice melting
ice formation
What is the overall effect of the stronger than normal trade winds typical of La Niña conditions? -swapping of the South Pacific high and low pressure zones from normal conditions -flipping of the South Pacific ocean current direction from normal conditions -raising of the South Pacific ocean temperature from normal conditions -lowering of the South Pacific ocean temperature from normal 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 __________. eddies fronts meanders
meanders
Ocean surface currents transfer about ________ of the total amount of heat from the tropics to the poles. one third three fourths two thirds one half one fourth
one-third
In subtropical gyres, western boundary currents have all of the following characteristics except being __________. relatively deep relatively wide relatively fast relatively warm
relatively wide
Deep ocean currents ___. -include deep water that rises in the North Atlantic and surface water that sinks in the Pacific and Indian Oceans -result from changes in water density (due to temperature and salt content) -are primarily driven by wind patterns
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 north; right south; right north; left.
south; left
The ocean's deep water is initially formed at the _________ and in _________ regions. surface; subpolar surface; subtropical ocean floor; subpolar ocean floor; subtropical
surface; subpolar
Which of the following currents does not belong with the others as part of the same gyre? the South Equatorial Current the Benguela Current the West Wind Drift the Agulhas Current the Brazil Current
the Agulhas Current
Which of the following is an example of a western boundary current of a subtropical gyre? the West Australian Current the Kuroshio Current the Labrador Current the Canary Current the California Current
the Kuroshio Current
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 temperature zones in the South Pacific under normal conditions the swapping of high and low pressure zones in the South Pacific under normal conditions the swapping of high and low temperature zones in the South Pacific under El Niño conditions the swapping of high and low pressure zones in the South Pacific under El Niño conditions
the swapping of high and low pressure zones in the South Pacific under El Niño conditions
The Ekman spiral is caused by: the wind and the Coriolis effect. pressure gradients. the wind and gravity. the pycnocline. density differences in the water column.
the wind and the Coriolis effect.
_____ is caused by density changes near the poles and equator.
thermohaline circulation
Deep ocean current movement is also known as __________. equatorial downwelling the Antarctic Divergence Ekman transport thermohaline flow Walker circulation
thermohaline flow
In the southern hemisphere, the direction of Ekman transport is always: to the right of the wind direction. at a 45° angle from the wind direction. perpendicular to the wind direction. to the east of the wind direction. to the left of the wind direction.
to the left of the wind direction.
Under which conditions are droughts and wildfires common in Australia? under La Niña conditions under Walker Circulation conditions under normal conditions under El Niño conditions
under El Niño conditions
Surface waters are pushed away from land and replaced by nutrient-rich bottom water through: sea breezes. downwelling. upwelling. convergence. land breezes.
upwelling.
The Gulf Stream is a ________ current that flows ________. cold; west warm; north warm; west cold; north warm; south cold; south
warm; north
The East Australian Current is a ________ current that flows ________. warm; south cold; north cold; south warm; east warm; north cold; east
warm; south
Warm core rings and cold core rings are associated with __________. equatorial countercurrents eastern boundary currents contour currents tropical cyclones western boundary currents
western boundary currents