Climate

Climate

Chapter 3 Section 2

Key Terms

• Convection-The transfer of heat in the atmosphere by upward motion of the air

• El Nino- the warming of waters off the west coast of South America

• Greenhouse effect- the theory that gases released by burning coal and petroleum trap solar energy, causing higher temperatures

Factors Affecting Climate

 WIND CURRENTS/OCEAN CURRENTS 

   Wind and ocean currents help distribute the sun’s heat from one part of the world to another. This is done through convection. Convection is the transfer of heat in the atmosphere by upward motion of the air.

Factors Affecting Climate 

WIND CURRENTS/OCEAN CURRENTS 

   Convection occurs when the sunlight heats the atmosphere. The heated air expands. A region of low air pressure is created by this expansion. Cooler denser air in a nearby high-pressure region rushes into the low-pressure area.

Multiple Choice

Wind and ocean currents help distribute the sun’s heat from one part of the world to another through ____________________, the transfer of heat in the atmosphere by upward motion of the air.

• convection

• cyclones

• connection

Factors Affecting Climate 

WIND CURRENTS/OCEAN CURRENTS 

   Ocean currents are like rivers flowing in the ocean. Warm water flows away from the equator toward the poles, and cold water flows back toward the equator. Winds blowing over the ocean currents are heated or cooled by the currents. The winds then affect the lands that the winds blow across.

Multiple Choice

____________________ are like rivers flowing in the ocean. Moving in large circular systems, ____________________ flows away from the equator out toward the poles, and ____________________ flows back toward the equator. They not only affect the temperature of an area, but they affect the precipitation as well.

• ocean currents; warm winter; cold summer

• ocean waves; warm water; cold air

• ocean currents; warm water; cold water

Factors Affecting Climate 

WIND CURRENTS/OCEAN CURRENTS 

 Currents also affect the precipitation in an area. Cold ocean currents flowing along a coastal region chill the air. Sometimes they prevent warm air and the moisture it holds from falling to earth.

Multiple Choice

Four major factors influence the climate of a region: ____________________, ____________________, ____________________, and ____________________.

• currents (wind and ocean), latitude, altitude, topography

• currents (wind and ocean), longitude, altitude, topography

• currents (wind and ocean), latitude, altitude, peanuts

ZONES OF LATITUDE

  How does latitude location affect climate?

Geographers divide the earth into three general regions of latitude: low or tropical, middle or temperate, and high or polar. Tropical regions are found on either side of the equator

Multiple Choice

Geographers divide the earth into three general zones of latitude: lower or ____________________, middle or ____________________, and high or ____________________. Lands in ____________________ zones are hot all year long. Lands in ____________________ zones are cold all year long. Lands in ____________________ zones have climates that can vary greatly from relatively hot to relatively cold.

• tropical, temperate, polar; tropical; polar; temperate

• tropical, temperate, polar; temperate; polar; polar

ZONES OF LATITUDE

   Lands in tropical regions are hot all year long. In some areas, a shift in wind patterns causes variations in climate. The high latitude or polar regions circle the North Pole and South Pole. They are cold all year. During summer in the polar regions, the temperature reaches a high of only 50° F.

ZONES OF LATITUDE

   The earth’s two temperate regions lie at the middle latitudes. They are between the tropics and the polar regions. Within the temperate regions, climates can vary greatly. The variations range from relatively hot to relatively cold. These variations occur because solar heating is greater in the summer than in the winter

ELEVATION/TOPOGRAPHY

  How does elevation affect climate?

   Another factor in determining a region’s climate is elevation, or distance above sea level. The air temperature drops as elevation increases. Climates above 12,000 feet become like those in Arctic areas.

ELEVATION/TOPOGRAPHY

  Landforms also affect climate. This is especially true of mountain areas. Remember that as winds move up the side of a mountain they cool. They also lose their ability to hold moisture and release rain or snow. By the time the winds reach the other side of the mountain, they are dry and become warmer as they flow down the mountain.

Multiple Choice

Another factor in determining the climate of a region is ____________________, or distance above sea level. As the distance above sea level increases, the air temperature ____________________.

• latitude; drops

• weatherability; drops

• altitude; drops

Multiple Choice

What happens to winds as they move up the side of a mountain?

• They heat up and produce strong storms.

• They cool and lose their ability to hold moisture.

Changes in Climate 

How does El Niño affect the weather?

   Climates change over time. Changes in climate are natural and the result of human activities.

Changes in Climate

   An example of a natural change is El Niño. This is warming of the waters off the west coast of South America. About every two to seven years, the eastern winds that blow over the central Pacific Ocean slow or reverse direction. This changes the ocean temperature and affects the weather worldwide.

Multiple Choice

Climate changes over time. The warming of water off the west coast of South America, known as ____________________, is a natural change in the climate.

• la nina

• el bano

• el nino

• la fogata

Changes in Climate

   Usually, these easterly winds bring seasonal rains and push warm ocean water toward Asia and Australia. In El Niño years, however, the winds push warm water and heavy rains toward the Americas. This can cause floods and mudslides there. At the same time Australia and Asia experience drought conditions.

Multiple Choice

What happens in the Americas during El Niño?

• There are droughts in the Americas. This can cause dust storms and water shortages there.

• There are heavy rains in the Americas. This can cause floods and mudslides there.

Changes in Climate

   When the winds blow in the opposite direction, to the west, the warmer waters are pushed to the lands on the western Pacific rim. This is called La Niña. La Niña causes increased precipitation in places such as India and increased dryness on the eastern side of the Pacific.

GLOBAL CLIMATE CHANGE

  What is global warming?

   Evidence shows that climates are changing around the world. Since the late 1800s, the temperature of the earth has increased by one degree Fahrenheit. Estimates suggest that temperature will increase from 3.2 to 7.2 degrees in the next century.
   Some argue that this warming is part of the earth's natural cycle.

GLOBAL CLIMATE CHANGE

   However, most climate scientists argue that global temperature increases are caused by the greenhouse effect. The greenhouse effect occurs when the layer of gases released by the burning of coal and petroleum traps solar energy. This causes higher temperatures in the same way that a greenhouse traps solar energy.

GLOBAL CLIMATE CHANGE

   The greenhouse effect and global warming will probably increase as more nations industrialize. If this trend continues, ice caps will melt, flooding some coastal areas and covering some islands. Weather patterns could also become more erratic.

Multiple Choice

Some scientists argue that global temperature increases are caused by the ____________________, the layer of gases released by the burning of coal and petroleum that traps solar energy, causing higher temperatures

• biosphere

• atmosphere

• greenhouse effect

• butterfly effect