chapter 7 one 1001

Which of the following is the only current that completely circumscribes Earth?

Antarctic Circumpolar

What is the main Antarctic current?

Antarctic Circumpolar Current

Which of the following currents is responsible for Peru becoming the largest producer of fish, from the sea, in the world?

Humboldt Current

Between summer and winter, which of the following currents reverses its flow direction?

Somali Current

Which of the following Atlantic Subtropical gyre boundary currents is split into two by a large landmass?

South Equatorial Current

What effect do the two different monsoon seasons have on the Indian Ocean surface currents?

They cause the currents to reverse direction.

If the Gulf Stream were to turn right into the Atlantic Ocean near the coast of South Carolina, the climate of the northeast United States would become ____ and the climate of Europe would become ____.

cooler; warmer

Downwelling can result from ______

converging surface currents

The global ocean conveyer belt circulation is most responsible for distributing what?

heat

What is a La Niña?

increased Walker Circulation in the Pacific Ocean

What is the most dramatic impact of an El Niño on the west coast of South America?

lack of upwelling

Of the following locations, where would upwelling be expected to occur? Choose all that apply.

-Where seamounts or tablemounts are present - In areas of diverging surface currents - Where there is a sharp bend in a coastline

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.

Ocean surface currents transfer about ________ of the total amount of heat from the tropics to the poles.

1/3

About what percent of the wind's energy is transferred to the ocean surface?

2%

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

80

An Ekman spiral is a balance between what two factors?

Coriolis effect and friction

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

D) Northern Hemisphere Subpolar Gyres A) South Pacific Subtropical Gyre F) South Atlantic Subtropical Gyre B) Indian Ocean Subtropical Gyre

The Benguela Current is an example of which of the following types of currents?

Eastern Boundary Current

The California Current is an example of which of the following types of currents?

Eastern Boundary Current

Why do areas along eastern boundary currents typically have cool, dry climates?

Eastern boundary currents are coming from the poles and contain colder water.

Coastal winds can cause upwelling or downwelling due to which of the following?

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?

Ekman transport

The false-color map of sea surface temperatures shown below is an example of which of the following features?

El Nino conditions

A breakdown of normal circulation due to wind reduction in the Pacific Ocean results in what?

El Niño

Which of the following methods are used to measure deep ocean currents directly?

Free-drifting Argo floats

Which of the following currents contributes to the South Eastern United States being humid?

Gulf Stream

Of the following statements about the Ekman spiral and Ekman transport, which is/are true? Choose all that apply.

In the deeper layers of the Ekman spiral, water can move in a direction opposite of the wind direction. Ekman transport can result in both upwelling and downwelling. Ekman transport is to the right of the wind direction in the Northern Hemisphere. The Coriolis effect causes surface waters to move at an angle relative to the wind direction.

Why does upwelling increase biological productivity?

It provides nutrients used by phytoplankton.

What is the most likely scenario if conveyer belt circulation shut down in the North Atlantic?

Polar temperatures would encroach south.

Which of the following methods are used to measure ocean surface currents directly?

Radio-transmitting float bottles Accidental spills from container ships

The observation of a hill of water within all subtropical gyres is an example of which of the following?

Subtropical convergence

Why do subtropical gyres rotate in one direction and subpolar gyres rotate in the opposite direction?

Subtropical gyres are generated by the westerlies and trade winds, and subpolar gyres are generated by the polar easterlies.

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

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

The Brazil Current is an example of which of the following types of currents?

Western Boundary Current

The Kuroshio (Japan) Current is an example of which of the following types of currents?

Western Boundary Current

The floats that are programmed to measure deep currents are called what?

argo

Offshore winds most likely result in which of the following?

coastal upwelling

Judge the following sentence according to the criteria given below: India's Southwest Monsoon provides abundant precipitation BECAUSE the air brought in from the Indian Ocean is warm and full of moisture.

correct

Judge the following sentence according to the criteria given below: The Equatorial Countercurrent is much better developed in the Pacific Ocean than in the Atlantic BECAUSE the Pacific Ocean basin is larger and more unobstructed than the Atlantic Ocean.

correct

Judge the following sentence according to the criteria given below: The temperatures across the Atlantic at different latitudes are much higher in Europe than in North America BECAUSE of the effects of heat transfer from the Gulf Stream.

correct

A drift current meter provides what info to researchers?

current speed and flow direction

What would happen to a hurricane passing over a cold core ring?

de-intensification

An increase in seawater density can be caused by a ________ in temperature or a/an ________ in salinity.

decrease; increase

Thermohaline circulation is driven by:

density differences

What is the driving force behind the generation of deep-water currents?

density differences

Converging surface waters are areas of ________ and ________ productivity.

downwelling, low

Which current in a gyre is shallow, slow, wide, and moves cold water?

eastern boundary current

What is an ecological benefit of downwelling?

export of dissolved oxygen to the deep ocean

During winter months, monsoon winds over the Indian Ocean:

flow from land to sea and are dry.

When Coriolis effect and gravity are balanced in a subtropical convergence, what is the result?

geostrophic current

Which of the following two factors cause geostrophic circulation within a gyre?

gravity and the Coriolis effect.

What is the name of the western boundary current of the North Atlantic subtropical gyre?

gulf stream

Which of the following methods are used to measure ocean surface currents indirectly?

pressure grandients

A reduction in atmospheric pressure differences across the Pacific Ocean results in what?

reduced wind across the basin

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

A gyre centered over 30 degrees north or south latitude is referred to as what?

subtropical

Where on the globe does deep-water formation occur?

the polar regions

The El Niño Southern Oscillation can best be described as:

the relationship between sea surface temperature and changing atmospheric pressure.

The Ekman spiral is caused by:

the wind and the Coriolis effect.

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

Which of the following is considered to be normal circulation in the Pacific Ocean?

walker circulation

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.

Which current in a gyre is deep, swift, and moves warm water?

western boundary current

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

western boundary currents

What is the generating force that starts surface currents?

wind