OCE Chap 7

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

80

A. Agulhas Current B. Benguela Current C. California Current D. Canary Current E. West Australian Current

Agulhas Current

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

A. California Current B. Canary Current C. Gulf Stream D. North Atlantic Current E. North Equatorial Current

California Current

An eastern boundary current is generally narrow and swift.

False

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

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

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

Gulf Stream

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.

A. thermohaline circulation B. density-driven circulation C. Antarctic Bottom Water D. Kuroshio Current E. North Atlantic Deep Water

Kuroshio Current

Identify the mismatched pair from the choices below.

Labrador Current, Humboldt Current

The Gulf Stream transports warm water into 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

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

Northern Hemisphere Subpolar Gyres, Indian Ocean subtropical, South Atlantic subtropical, South Pacific subtropical(NOT NORTH ATLANTIC AND PACIFIC)

Which of the following statements is true of surface ocean currents?

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

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 instrument used to measure current flow rates.

True

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

True

Deep ocean water masses have characteristic temperatures and salinities.

True

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

True

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

True

The main current in Antarctic waters is the Antarctic Circumpolar Current, also called the West Wind Drift.

True

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

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

Of the following currents, which ones are parts of the South Atlantic Subtropical Gyre?

West Wind Drift, south equatorial current, benguela current, brazil current

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

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

all but deep ocean currents are faster than ocean surface currents

Surface ocean currents ___.

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

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

West Wind Drift

cold current, polar latitudes, southern hemisphere

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

Downwelling can result from __________.

converging surface currents

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

denser

Thermohaline circulation is driven by

density differences.

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

density differences; differences in salinity and temperature

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

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

eddies

Of the following statements about Ekman spiral and Ekman transport, which is/are true?

everything but ekman transport is the same as thermohaline flow.

Cool ocean currents ___.

generally flow from high latitudes towards the equator

Which type of current flow moves in a circular path around a subtropical convergence, reflecting Ekman transport, gravity, and the Coriolis effect?

geostrophic circulation

Geostrophic circulation within a gyre driven by:

gravity and the Coriolis effect

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.

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

gyre

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

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

meanders

upwelling

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

Ekman transport

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

Gulf Stream

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 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

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

temperature; salinity

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

the Gulf Stream, peru current, 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 pressure zones in the South Pacific under El Niño conditions

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

upwelling.

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

western boundary currents