1. Earth-Sun Relationships

2. Weather and Climate
Weather is a the condition of the atmosphere in one place during a limited period of time
Climate is the term for the weather patterns that an area typically experiences over a long period of time

3. What determines climate?
Climate is determined by many things, but most importantly it is determined by the Earth’s position in relation to the sun

4. The Earth’s Axis The Earth spins on it’s axis
The axis is an imaginary line running from the North to the South pole through the planet’s center
The axis is at an angle of about 23.5 degrees

5. Temperature The angle of the axis affects the temperature
Temperature is the measure of how hot or cold a place is
The temperature is measured either in Fahrenheit or Celsius

6. Rotation and Revolution
The Earth spins on it’s axis and makes one complete rotation every 24 hours
Earth rotates from east to west
The Earth also revolves around the sun
It takes 365 days for the Earth to make one complete revolution around the sun
The Earth’s tilt and it’s revolution cause changes in seasons

7. The Greenhouse Effect
The greenhouse effect is when the Earth’s atmosphere traps some of the suns radiation
Most of the sun’s radiation is reflected back into space, however enough seeps through to warm the land, water, and air

8. Global Warming
The rise in recent decades of the Earth’s temperatures is believed to be caused by global warming which is believed to be caused in part by human activities
Some scientists, however, believe that global warming is a natural cycle, not caused by humans
Global warming is when there is a rise in the amount of Carbon Dioxide (CO2)in the atmosphere because of the burning of fossil fuels (coal, natural gas, and oil)
CO-2 absorbs more heat reflected by the Earth, trapping it in the Earth’s atmosphere

9. The Latitude Zones
Because of the rotation and tilt of the Earth, the sun hits the Earth’s latitudes for certain periods of time
The Low latitudes are between the Tropics of Cancer and Capricorn (23 ½ degrees north and south latitude)
The low latitudes receive the direct rays of the sun year-round
The low latitudes have warm, hot climates

10. High Latitudes The high latitudes are at the Earth’s polar areas
When either the Northern or Southern Hemisphere is tilted toward the sun, the pole receives continuous sunlight (causes the “midnight” sun)

11. The Mid-latitudes The mid-latitudes have the most variable weather
The mid-latitudes are found between the Tropics of Cancer and Capricorn and the Arctic and Antarctic circles
The mid-latitudes experience dramatic seasonal weather changes
In the summer they receive the warm air from the tropics and in the winter, the cool air from the poles

12. Elevation Elevation also plays a role in climate
The Earth’s atmosphere thins as altitude increases and thinner air retains less heat

13. Wind and Water The wind and water also impact the Earth’s climate
Wind – air moving across the Earth’s surface
Wind occurs because the sun heats up the Earth’s atmosphere unevenly cause high pressure and low pressure
The wind helps to distribute the sun’s heat around the planet

14. The impact of water
Mountain ranges can cause heavy precipitation on the windward side, and almost no precipitation on the leeward side
As a result, the climate on one side of a mountain is cool and wet, and the other side is warm and dry

15. Climate Regions

16. Different Regions
Geographers divide the Earth into several different climate regions:
Tropical
Dry
Mid-latitude
High latitude
Highlands
***Each of these regions are further divided into smaller ones

18. The smaller regions
The smaller regions are characterized by the natural vegetation
Natural vegetation is the plant life that grows in an area where the natural environment is unchanged by human activity

19. Tropical Climates
Tropical climates are found in or near the low latitudes
The most widespread kinds of tropical climate regions are tropical rain forests and tropical savannas
Lush vegetation is common in tropical climates and wildlife is also abundant
Rain occurs almost daily in tropical rain forests
In tropical savannas there are dry winters and wet summers with high temperatures year-round

20. Dry Climates There are two types of dry climates: Desert climates
Steppe climates

21. Deserts are dry areas with sparse plant life
Rainfall in deserts rarely exceed 10 inches
Desert vegetation consists of scattered shrubs and cactus
In some areas there may be an oasis, which is an area of lush vegetation
A steppe climate is a large, treeless grassland that typically borders a desert
Annual precipitation is usually between 10 and 20 inches

22. Mid-latitude Climates
Mid-latitudes include four temperate regions:
Marine West Coast
Mediterranean
Humid Sub-tropical
Humid Continental

23. Marine West Coast
Includes: Pacific Coast of North America, most of Europe, and parts of S.A., Africa, Australia, and New Zealand
Ocean winds bring cool summers and damp winters
Natural vegetation includes coniferous and deciduous trees
Coniferous – have cones
Deciduous – have broad leaves, change colors, and drop their leaves in autumn
Most marine west coast climates have mixed forests

24. Mediterranean
This includes land surrounding the Mediterranean Sea, some areas of California, and parts of southern Australia
Have rainy, mild winters and hot, sunny summers
Natural vegetation includes chaparral, thickets of woody bushes and short trees

25. Humid Sub-tropical
Southeast U.S., and southeast parts of South America and Asia
Brings short, mild winters, and nearly year-round rain
Humidity levels are high in these areas because of the wind patterns and high pressure related to nearby oceans
Natural vegetation consists mostly of prairies, or inland grasslands, and forests of deciduous trees

26. Humid Continental
Southern Canada, Western Russia, and northeastern China
Landforms influence this type of climate region
Vegetation is similar to that found in Marine West Coast
As you travel further north, the winters are more severe and summers are shorter

27. High Latitude Climates
High latitude climates include subarctic and tundra climate regions
Freezing temperatures are common
Vegetation is limited
Subarctic climate region is just below the Arctic Circle – winters are bitterly cold and summers are short and cool
Only a thin layer of soil thaws each year – below it is permafrost – permanently frozen subsoil
Can support some needled evergreens

28. Tundra Climate
Also a high latitude climate, tundra climate regions are very cold
Winter darkness and bitter cold last for half the year, and the constant light in the summer but little heat
Vegetation is limited to low bushes, very short grasses, mosses, and lichens

29. Highlands Climate
Elevation can also determine a climate region, regardless of latitude
What characterizes highlands climate is the thinning of the altitude
Natural vegetation varies because of the changes of temperature as one goes up the mountain