Currents and Climates

Surface climates greatly affect the climate in many parts of the world.

Some surface currents ____or____ coastal areas year-round.

Warm or coolOther surface currents sometimes change their

_________ pattern.CirculationChanges in circulation patterns cause changes

in ________ that affect the ______ in many parts of the world.

Atmosphere, climate

Warm-Water Currents and Climate

• What are surface currents classified as?

• Warm-water currents or cold-water currents.

Upwelling• What happens when local wind patterns blow along the northwest coast of

South America?• They cause local surface currents to move away from the shore.• What replaces the warm water when this happens?• Deep, nutrient rich cold water.• What occurs due to this action?• Upwelling, which is what?• A process in which cold, nutrient-rich water from the deep ocean rises to the

surface and replaces warm surface water.• What are the nutrients from the deep ocean composed of?• Iron and nitrate• When these chemicals are brought to the sunny surface, what do they help?• They help tiny plants grow through the process of photosynthesis.• Why is the process of upwelling important to organisms?• The nutrients that are brought to the surface, support the growth of

phytoplankton and zooplankton, which support organisms such as fish and seabirds.

Upwelling

El Nino

El Nino• What happens every 2 to 12 years with the South Pacific trade

winds?• They move less warm water to the western Pacific than they usually

do.• What happens to the surface-water temperatures along the coast of

South America as a result of this change?• They rise• Gradually this warming spreads_________.• Westward• What is this periodic change in location of warm and cool surface

waters in the Pacific Ocean called?• El Nino• How long can El Nino last?• Year or longer

• El Nino not only affects the surface waters but also changes the interaction of the ________and the _________, which in turn does what?

• Ocean and atmosphere• Changes global weather patterns• What follows El Nino sometimes?• La Nina, which is a periodic change in the eastern Pacific

Ocean in which the surface-water temperatures becomes unusually cool.

• La Nina also affects __________patterns.• Weather

Effects of El Nino

• What happens when the weather patterns are altered by El Nino?

• Disasters such as: flash floods and mudslides in areas of the world that usually get little rainfall- some regions that usually get a lot of rain experience droughts.

Studying and Predicting El Nino• Studying and predicting El Nino can be difficult because it occurs every 2 to

12 years.• How is one way scientists collect data to predict an El Nino?• Through a network of buoys operated by NOAA (National Oceanic and

Atmospheric Administration)• The buoys are anchored to the ocean floor along where?• The Earth’s equator.• How do the buoys work?• They record data about surface temperature, air temperature, currents and

winds.• The buoys transmit some of the data on a daily basis to __________through

a _________in space.• NOAA, satellite• When the buoys report that the South Pacific trade winds are not as strong

as they usually are or that the surface temperatures of the tropical oceans have risen, scientists can predict that an _______is likely to occur.

http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/sstanim.shtml

Waves• What are the 2 parts of a wave?• Crest and trough• ____________is the highest point of a wave.• Crest• ____________is the lowest point of a wave.• Trough• ____________are waves that form when a large volume of ocean water is

suddenly moved up or down.• Tsunamis• ____________waves that form in the open ocean; white foaming waves

with very steep crests that break in the open ocean before the waves get close to the shore.

• Whitecaps• ___________is a local rise in sea level near the shore that is caused by

strong winds from a storm, such as a hurricane• Storm surge

Tides• __________are daily changes in the level of ocean water.• Tides• What influences tides?• The sun and the moon• When was a scientific explanation of the moon phases and their

relationship to the tides given?• 1687 by Sir Isaac Newton and his principle of gravitation.• The ________of the moon pulls on every particle of the Earth.• Gravity• Why is the gravitational pull on liquids more noticeable than on

solids?• Liquids move more easily.

High Tide and Low Tide

• How often tides occur and the difference in tidal levels depends on what?

• The position of the moon as it revolves around the Earth .

• When is the moon’s pull the strongest?

• When it is on the part of the Earth directly facing the moon.

• When part of the ocean is directly facing the moon, the water there bulges toward the moon.

• These bulges are called_________• High tides• When high tides occur, water is drawn away from the

area between the high tides, which causes __________to form.

• Low tides• Why do tides occur at different locations on Earth?• The Earth rotates more quickly than the moon revolves

around the Earth.

Tidal Variations• A _________is the difference between levels of ocean water at high tide

and low tide.• Tidal range• Which tides occur when the sun, Earth, and moon are aligned?• Spring tides (largest daily tidal range and occur during new and full moons,

or every 14 days.• The first time spring tides occur when the moon is __________ the sun and

Earth.• Between• The second time spring tides occur is when the _______and the _______

are on __________sides of the Earth.• Moon, sun, opposite• When the sun, Earth and moon form a ________ , neap tides occur.• 90 degree angle• _____________are tides with the smallest daily tidal range and occur during

the first and third quarters of the moon.• Neap tides