surface ocean currents

surface currents

Ocean water moves in predictable ways along the ocean surface. Surface currents can flow for thousands of kilometers and can reach depths of hundreds of meters. These surface currents do not depend on weather; they remain unchanged even in large storms because they depend on factors that do not change. Surface currents are created by three things: global wind patterns the rotation of the Earth the shape of the ocean basins Surface currents are extremely important because they distribute heat around the planet and are a major factor influencing climate around the globe.

shape of the ocean basins

When a surface current collides with land, the current must change direction. In the Figure 1.1, the Atlantic South Equatorial Current travels westward along the Equator until it reaches South America. At Brazil, some of it goes north and some goes south. Because of Coriolis effect, the water goes right in the Northern Hemisphere and left in the Southern Hemisphere.

global wind patterns

Winds on Earth are either global or local. Global winds blow in the same directions all the time and are related to the unequal heating of Earth by the Sun that is, more solar radiation strikes the Equator than the polar regions and the rotation of the Earth that is, the Coriolis effect. Coriolis was described in the chapter Earth as a Planet. The causes of the global wind patterns will be described in detail in the chapter Atmospheric Processes. Water in the surface currents is pushed in the direction of the major wind belts: trade winds: east to west between the Equator and 30o N and 30o S westerlies: west to east in the middle latitudes polar easterlies: east to west between 50o and 60o north and south of the Equator and the north and south pole

local surface currents

The surface currents described above are all large and unchanging. Local surface currents are also found along shorelines (Figure 1.3). Two are longshore currents and rip currents. Rip currents are potentially dangerous currents that carry large amounts of water offshore quickly. Each summer in the United States at least a few people die when they are caught in rip currents. Longshore currents move water and sediment parallel to the shore in the direction of the prevailing local winds.

textbook_image

gyres

You can see on the map of the major surface ocean currents that the surface ocean currents create loops called gyres (Figure 1.2). The Antarctic Circumpolar Current is unique because it travels uninhibited around the globe. Why is it the only current to go all the way around? Click image to the left or use the URL below. URL: The major surface ocean currents.

textbook_image

textbook_image

instructional diagrams

description_image

The diagram below shows the types of Ocean current. An ocean current is a continuous, directed movement of seawater generated by forces acting upon this mean flow, such as breaking waves, wind, the Coriolis effect, cabbeling, temperature and salinity differences, while tides are caused by the gravitational pull of the Sun and Moon. Depth contours, shoreline configurations, and interactions with other currents influence a current's direction and strength. Ocean currents flow for great distances, and together, create the global conveyor belt which plays a dominant role in determining the climate of many of the Earths regions. More specifically, ocean currents influence the temperature of the regions through which they travel. For example, warm currents traveling along more temperate coasts increase the temperature of the area by warming the sea breezes that blow over them. Perhaps the most striking example is the Gulf Stream, which makes northwest Europe much more temperate than any other region at the same latitude. Another example is Lima, Peru where the climate is cooler (sub-tropical) than the tropical latitudes in which the area is located, due to the effect of the Humboldt Current.

description_image

This diagram shows the way ocean and waves move. Most ocean waves are caused by winds. A wave is the transfer of energy through matter. A wave that travels across miles of ocean is traveling energy, not water. Ocean waves transfer energy from wind through water. The energy of a wave may travel for thousands of miles. The water itself moves very little. Ocean water also moves from the deep sea to the ocean surface. Places where this happens are called areas of upwelling. The marine life and the climate can be affected as the cold water makes its way up from the deep.

questions

the great pacific garbage patch is

-->  a) the center of the north pacific gyre where trash and pollutants accumulate.

b) the center of the south pacific gyre where trash and pollutants accumulate.

c) the region that lines the continents around the pacific where trash and pollutants are released.

d) none of these.

surface currents are a result of

a) global wind patterns

b) earths rotation

c) shape of ocean basins

-->  d) all of the above

coriolis effect is

-->  a) the apparent motion of freely moving objects as earth rotates beneath them.

b) the force of earths rotation pushing on freely moving objects.

c) what happens when freely moving objects, like air and water, meet high and low pressure cells.

d) none of these.

the global wind belts and their directions in order from the equator to the north pole are

a) trade winds, west to east; westerlies, east to west; polar easterlies, west to east.

b) westerlies, east to west; trade winds, west to east; polar easterlies, east to west.

-->  c) trade winds, east to west; westerlies, west to east; polar easterlies, east to west.

d) westerlies, west to east; trade winds, east to west; polar easterlies, west to east.

wind in the global wind belts

a) forms a gyre, like the surface ocean currents below it.

-->  b) blows around the planet, with alternating bands blowing in opposite directions.

c) blow west to east around the planet.

d) blow west to east in the northern hemisphere and east to west in the southern hemisphere.

the northern hemisphere gyres rotate counter clockwise.

a) true

-->  b) false

when a surface ocean current traveling from east to west across the ocean runs into a continent, it will turn _ in the northern hemisphere and _ in the southern hemisphere.

a) left, left

b) left, right

-->  c) right, left

d) right, right

if you get caught in a rip current, what should you do?

a) swim straight in to shore.

b) swim straight out from the shore and then back in.

c) ride the rip current until it carries you to shore.

-->  d) swim parallel to the shore and then swim back in.

how does a water molecule move that is stuck in a longshore current?

-->  a) it goes into shore at an angle and comes away from shore perpendicular to the beach.

b) it goes into shore at an angle and comes away from shore at an angle.

c) it goes into shore perpendicular to the beach and out from shore perpendicular to the beach.

d) it moves straight along the shore.

diagram questions

question_image

In which direction do the major surface currents flow in the Northern Hemisphere?

a. Counterclockwise

b. West

-->  c. Clockwise

d. East

question_image

In what direction does the majority of the water flow in the Southern Hemisphere?

a. West

b. clockwise

-->  c. counterclock wise

d. East

question_image

What current is connected to the Greenland Current?

-->  a. Labrador Current

b. North Atlantic Drift

c. North Atlantic Current

d. Gulf Stream

question_image

Which ocean current runs from the east coast of North America to Northern Europe?

-->  a. Gulf Stream

b. North Atlantic Drift

c. South Equatorial Current

d. North Equatorial Current

question_image

How many color/s of arrow is/are shown in the picture?

-->  a. 1

b. 3

c. 4

d. 2

question_image

Which direction do currents flow in the Northern Hemisphere?

a. downward

-->  b. clockwise

c. vertical

d. counterclockwise

question_image

What direction does the majority of the water flows in the North Hemisphere?

a. East

b. West

c. counterclockwise

-->  d. clockwise

question_image

In what direction does the majority of the water flow in the Southern Hemisphere?

a. East

b. clockwise

-->  c. counterclockwise

d. West

question_image

How many currents flow around Australia?

a. 4

b. 1

c. 3

-->  d. 2

question_image

How many types of lines are shown in the picture?

a. 2

b. 1

-->  c. 3

d. 4

question_image

What stream shown comes out of the North Atlantic Drift?

a. North Equatorial

b. Alaska

c. North Pacific

-->  d. Norwegian

question_image

What type of water rises to the surface during an upwelling?

a. Bottom water

-->  b. Deep water

c. Intermediate water

d. Surface water

question_image

What are the arrows showing in this diagram?

a. The density of the water

b. The movement of fish and other marine animals

c. The type of water

-->  d. The movement of water molecules

question_image

Which continent does the circumpolar deep water go to?

-->  a. Antarctica

b. Europe

c. North America

d. Atlanta

question_image

How many arrows there are below?

a. 20

b. 45

-->  c. 49

d. 32

question_image

How many types of surface water can you find in the diagram?

a. 4

b. 2

-->  c. 3

d. 1

question_image

How many cold currents are in the world?

a. 7

-->  b. 8

c. 6

d. 9

question_image

How many continents in the world?

a. 9

-->  b. 7

c. 3

d. 5

question_image

What cold current passes through the pacific coast of the US?

a. Benguela

b. Brazil

c. Gulf Stream

-->  d. Californian

question_image

Which Ocean Movement is off of the United States East Coast?

a. Californian

b. Brailian

c. Kuro Siwo

-->  d. Gulf Stream

question_image

Which kind of current is the Gulf Stream?

a. Cold Current

-->  b. Warm Current

c. Slow Current

d. Fast Current

question_image

What is an example of a cold current?

a. Gulf Stream

b. Kuro Siwo

-->  c. Peruvian

d. East Australian

question_image

From the diagram, how many types of currents does Australia have?

a. 4

b. 1

c. 3

-->  d. 2

question_image

What cold current passes through the pacific coast of the US?

-->  a. Californian

b. South Equatorial

c. Gulf Stream

d. Peruvian

question_image

Which ocean movement is located just below the Californian ocean movement?

a. West Austalian

-->  b. South Equatorial

c. Gulf stream

d. Labrador

question_image

The California cold current moves in what direction?

a. northward

b. westward

c. eastward

-->  d. southward

question_image

In the Robinson Projection, what flows into the N. Atlantic Drift?

-->  a. Gulf Stream

b. South Equatorial

c. Alaska

d. N. Equatorial

question_image

How many types of Equatorial currents are there?

a. 1

-->  b. 3

c. 4

d. 2

question_image

The earth is divided in how many parts from the diagram?

-->  a. 6

b. 4

c. 5

d. 3

question_image

What cold current passes through the pacific coast of the US?

a. Gulf Stream

b. Labrador

-->  c. Californian

d. Peru