Factors That Influence Climate

Read the text on the factors that influence climate and answer the questions below. Be certain to answer all questions in complete sentences. Follow all the rules of the English language.

Four major factors influence the climate of a region: wind and ocean currents, latitude, elevation, and topography.

Wind and Ocean Currents

Wind and ocean currents help distribute the sun’s heat from one part of the world to another through convection, the transfer of heat in the atmosphere by upward motion of the air.   As sunlight heats the atmosphere, the air expands, creating a zone of low air pressure.  Cooler dense air in a nearby high pressure zone rushes into the low-pressure area, causing wind.

Global wind patterns are caused by the same kind of circulation on a larger scale.  The hot air flows toward the poles, and the cold air moves toward the equator.  The winds would blow in straight lines, but since the earth rotates they are turned at an angle.  In the Northern Hemisphere, they turn to the right.  In the Southern Hemisphere, they turn to the left.  This bending of the wind is called the Coriolis effect.

Ocean currents are like rivers flowing in the ocean.  Moving is large circular systems, warm waters flow away from the equator toward the poles, and cold water flows back toward the equator.  Wind blowing over the ocean currents affect the climate of the lands that these winds cross.  For example, the warmth of the Gulf Stream and the North Atlantic Drift help to keep the temperature of Europe moderate.  Even though much of Europe is as far north as Canada, it enjoys a much milder climate than Canada.

Ocean currents affect not only the temperature of an area, but also the amount of precipitation received.  Cold ocean currents flowing along a coastal region chill the air and sometimes prevent warm air and the moisture it holds from falling to earth.  The Atacama Desert in South America and the Namib Desert in Africa, for example, were formed partly because of cold ocean currents nearby.

Latitude

Geographers divide Earth into three general zones of latitude: low or tropical, middle or temperate, and high or polar.  Tropical zones are found on either side of the equator.  They extend to the tropic of Cancer in the Northern Hemisphere and the Tropic of Capricorn in the Southern Hemisphere.  Lands in tropical zones are hot all year long.  In some areas, a shift in wind patterns causes variations in the seasons.  For example, Tanzania experiences both a rainy season and a dry season as Indian Ocean winds blow in or away from the land.

The high latitude polar zones, which encircle the North Pole and South Pole, are cold all year.  Summer temperatures in the polar regions may reach only as high as 50 degrees Fahrenheit. 

The Earth’s two temperate zones like at the middle latitudes, between the tropics and the polar regions.  Within the temperate zones, climates can vary greatly, ranging from relatively hot to relatively cold.  These variations occur because solar heating is greater in the summer than in the winter.  So summers are much warmer.

Elevation

Another factor in determining the climate of a region is elevation, or distance above sea level.  You would think that the closer you get to the sun, the hotter it would become.  But as altitude increases, the air temperature  drops (about 3.5 degrees Fahrenheit for every 1,000 feet).  Therefore, the climate gets colder as you climb a mountain or other elevated location.  Climates above 12,000 feet become like those Arctic regions – with snow and ice.  For example, Mount Kilimanjaro in East Africa is capped by snow all year long.

Landforms/ Topography

Landforms also affect climate.  This is especially true of mountain areas.  Remember that moisture-laden winds cool as they move up the side of a mountain, eventually releasing 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.

1) How do wind and ocean currents affect temperature?

2) What is the cause of the Coriolis effect?

3) In addition to affecting temperature, what other feature of climate is affected by ocean currents?

4) List the three main climate zones on Earth and their MAIN characteristic in the following way:

 

Name of climate zone: main characteristic

5) How is it possible for a mountainous region in the tropical climate zone to have temperatures similar to a high or polar zone?

6) Use your electronic device or laptop to define the term "rain shadow".

7) Of the four factors (categories) that affect climate, which category does a "rain shadow" fall into?