Oceanography Chapter 7

Which of the following are western boundary currents?

-Brazil Current -Kuroshio Current -East Australia Current

What factor(s) drive(s) Ekman transport?

-Coriolis effect -wind

Which of the following statements is/are true regarding surface ocean currents?

-Gyres in the Southern Hemisphere rotate counterclockwise. -Cold currents flow at high latitudes or from higher latitudes toward the equator

Which of the following statements is/are true regarding subtropical convergence?

-Subtropical convergence is caused by the clockwise rotation of each gyre in the northern hemisphere. -Subtropical convergence produces a hill of piled up water in the center of each gyre in the northern hemisphere that is deflected towards the west. -Subtropical convergence causes a bulge of surface water that can be as high as 2 meters.

On a west coast in the Northern Hemisphere, what happens to surface waters when winds blow from the south?

-Surface waters move onshore. -Downwelling occurs.

On a west coast in the Northern Hemisphere, what happens to surface waters when winds blow from the north?

-Upwelling occurs. -Surface waters move offshore.

Which of the following conditions would you expect to find off the coast of Peru under normal, or neutral, El Niño-Southern Oscillation (ENSO) conditions?

-abundant anchovies -dry, clear conditions -shallow thermocline

Surface ocean currents ___.

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

Which of the following are true of western boundary currents?

-deep, as compared to eastern boundary currents -fast, as compared to eastern boundary currents

Which of the following conditions would be expected for the eastern Pacific during an El Niño event?

-floods -sea level rise -reversed Walker circulation -a deeper thermocline

Actual geostrophic flow is created by which of the following?

-gravity -Coriolis effect -friction

Which of the following conditions would be expected for the western Pacific during an El Niño event?

-high atmospheric pressure -weaker trade winds -wildfires

Why does the west coast of South Africa have high biological productivity?

-lots of coastal upwelling -high concentrations of nutrients in the surface water

Which factor(s) below drive(s) and shape(s) the pattern of surface ocean currents?

-shape of the ocean basins -Coriolis effect -wind

Which of the following are true of eastern boundary currents?

-wide, as compared to western boundary currents -weak, as compared to western boundary currents -they flow along the more gradual slope of the hill of water

As shown in NASA satellite data, in what years were the two most recent strong El Niño events?

1997-1998 and 2015

In which direction does the surface current move in relation to the wind in the Southern Hemisphere?

45 degrees to the left

Using the T-S diagram shown above, if a water mass has a density of 1.0280 g/cm3 and a salinity of 35.3 ppt, what is its temperature?

5 degrees Celsius

In locations where North Atlantic Deep Water, Antarctic Bottom Water, and Antarctic Intermediate Water are all found, how would they be arranged vertically in the water column?

Antarctic Bottom Water would be on the bottom, North Atlantic Deep Water would be in the middle, and Antarctic Intermediate Water would be on the top.

Water with which of the following characteristics would be the densest?

Cold water with high salinity would be the densest.

Why do the lengths of the arrows in the Ekman spiral get shorter and shorter as you move deeper into the water column?

Deeper water moves at a slower speed due to friction.

The thermocline is _________________.

a steep temperature gradient in the ocean that separates deeper cold water from warmer upper water

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

In the figure above, which of the labeled currents are warm water currents?

F E B

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 ocean current is the strongest and fastest ocean current in the world?

Gulf Stream

In the figure above, which of the labeled currents are eastern boundary currents?

H N C

Warm ocean currents ___.

are warmer than the surrounding water

During La Niña, what happens to the Pacific Warm Pool?

It gets pushed farther west.

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.

Which of the following water masses has the highest average salinity?

Mediterranean Intermediate Water

In the figure above, which of the labeled currents are shallow, weak, and slow currents?

N H

In the figure above, which of the following labeled currents is/are part of the South Atlantic Gyre?

N M

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

North Atlantic Deep Water

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.

Which of the following currents goes all the way around the world without being interrupted by land?

West Wind Drift

In the figure above, if this is a western-facing coast of the Northern Hemisphere, which wind pattern would cause coastal downwelling?

Wind C

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

denser

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

Cool ocean currents ___.

generally flow from high latitudes towards the equator

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

The subtropical gyres ___.

play a large role in climate

Deep ocean currents ___.

result from changes in water density (due to temperature and salt content)

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

temperature; salinity

What causes western intensification?

the rotation of Earth from west to east

What is the Southern Oscillation?

the swapping of high and low pressure zones in the South Pacific under El Niño conditions

In the figure above, depicting a hypothetical wind direction in an ideal world. The iceberg broke off from the Greenland Ice Sheet and floated into the ocean. Under the prevailing wind conditions, in which direction would the iceberg be pushed?

toward D

Refer the figure above. In which direction would the entire surface current underneath the Greenland iceberg be expected to travel?

toward E

Under which conditions are droughts and wildfires common in Australia?

under El Niño conditions

In the figure above, if this is a western-facing coast of the Southern Hemisphere, which wind pattern would cause coastal upwelling?

wind C