OCN 100 Ch 7 study guide

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below. A. Agulhas Current B. Benguela Current C. California Current D. Canary Current E. West Australian Current

A

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

Denser Extended Answer: The cooling of water at the ocean surface causes the temperature to decrease, which, in turn, causes the water molecules to become more compacted (denser) and potentially sink.

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 Extended answer: The Gulf Stream is a western boundary current in the North Atlantic Subtropical Gyre, and transports warm water away from the tropics.

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

Gyre Extended answer: An ocean gyre is any large system of rotating ocean currents. In the surface layer of the world ocean, there are five subtropical gyres and several smaller gyres.

The Gulf Stream transports warm water into the __________.

North Atlantic Extended Answer: The Gulf Stream is a western boundary current that transports warm water from the tropics toward the North Atlantic.

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

North Atlantic Deep Water Extended Answer: The North Atlantic Deep Water is a subsurface current that forms as a result of the sinking of cooler, denser water in the North Atlantic.

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

Thermohaline circulation is driven by:

density differences

Fluctuations in the flow of the Gulf Stream current result in curving loops of water known as __________.

meanders Extended Answer: The Gulf Stream moves around in a wiggle-like fashion due to differences in densities between cold and warm water systems.

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

temperature; salinty Extended Answer: The term thermohaline (thermo = heat, haline = salt) refers to density differences among water masses mostly influenced by temperature and salinity

The Ekman spiral is caused by:

the wind and the Coriolis effect.

Which of the following is a western boundary current? -Canary Current -Brazil Current -California Current -Benguela Current -Peru Current

-Brazil Current

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

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

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

-South Atlantic Subtropical Gyre -Indian Ocean Subtropical Gyre -South Pacific Subtropical Gyre -Northern Hemisphere Subpolar Gyres Extended Answer: The smaller Northern Hemisphere subpolar gyres flow in the opposite direction from their nearby, larger subtropical gyres. This is caused by the prevailing westerlies blowing water into high northern latitudes, where the polar easterlies blow the water back the other way, making the Northern Hemisphere subpolar gyres flow counterclockwise.

Of the following currents, which ones are parts of the South Atlantic Subtropical Gyre? -West Australian Current -West Wind Drift -Benguela Current -Brazil Current -South Equatorial Current -Agulhas Current

-West Wind Drift -Benguela Current -Brazil Current -South Equatorial Current

Match the term or person with the appropriate phrase. West Wind Drift -cold current, polar latitudes, southern hemisphere -cold current, southern hemisphere, temperate latitudes -cold current, northern hemisphere, temperate latitudes -northern hemisphere, temperate latitudes, warm current

-cold current, polar latitudes, southern hemisphere

Match the term or description with the appropriate phrase. upwelling -water flow driven by gravity and modified by the Coriolis force -net water movement to the left or right of the direction of the wind -movement of water from the bottom to the top of the water column -movement of water from the top to the bottom of the water column

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

Match the term or person with the appropriate phrase. Kuroshio Current -cold current, northern hemisphere, temperate latitudes -cold current, polar latitudes, southern hemisphere -cold current, southern hemisphere, temperate latitudes -northern hemisphere, temperate latitudes, warm current

-northern hemisphere, temperate latitudes, warm current

Examine the five words and/or phrases and determine the relationship among the majority of words/phrases. Please identify the word and/or phrase that does NOT fit the pattern. Enter only the letter of the answer (caps, no period, and not the full entry) in the field below.. A. California Current B. Canary Current C. Gulf Stream D. North Atlantic Current E. North Equatorial Current in the Atlantic Ocean

A

Compared to an eastern boundary current in a gyre, which of the following statements is true for a western boundary current? -deeper current -narrower current -warmer water -increased current velocity -All the above statements are true of western boundary currents.

All the above statements are true of western boundary currents.

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

Eddies Extended Answer: Eddies or water rings are sections of moving water that swirl off from the main Gulf Stream current and loop back on themselves, something akin to whirlpools.

Thermohaline circulation is wind-driven.

False

True or False: An eastern boundary current is generally narrow and swift.

False

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

False

One of the world's most powerful currents, located off the east coast of the United States, is the __________.

Gulf Stream Extended Answer: The Gulf Stream is a western boundary current and is part of the North Atlantic subtropical gyre.

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

Surface currents form circular patterns in the major ocean basins called "gyres."

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

True