Ch. 3 “Climate and Vegetation”

Ch. 3.1 “Seasons and Weather”

Seasons

• Seasons are determined by two factors:1. Earths tilt

2. Earths revolution around the sun

• Solstice: – Summer marks

longest day– Winter marks the

shortest day

• Equinox:– Both day and night are

equal all over world– Marks the beginning of

spring and fall

Weather

• Weather: condition of atmosphere at a specific time.

• Climate: atmospheric condition over a period of time.

Weather Factors• 1. cloud cover• 2. landforms & bodies of water• 3. elevation• 4. air movement • 5. water vapor

• Precipitation: falling water in the form of rain or snow (3 types)

Convectional- rain forest Orographic- coastal Frontal- great plains

Weather Extremes

• 5 Different extremes1. Hurricanes

2. Tornados

3. Blizzards

4. Droughts

5. Floods

Hurricane/Typhoons

• Storms that form over warm ocean waters.

• Take days to develop and are easy to track

Tornados

• Powerful, funnel shaped, column of spiraling air.

• Come from powerful thunderstorm.

• Form quickly with little warning

Blizzards

• Heavy snow storm with winds of 35+ mph.– Great Lakes area is

snowbelt• Avg. 37 ½ feet per

year.

Droughts

• A long period of time without rain or minimum rainfall

• Results in crop failures and reduces levels of water storage.

• In severe cases can cause famine.

Floods

• Occur when:– river banks can not

hold river water– or the ground

becomes saturated during a heavy storm.

Ch. 3.2 “Climate”

• 5 major factors that influence climate:1. Wind currents

2. Ocean currents

3. Latitude

4. Elevation

5. Topography

1. Wind Currents• Convection: distribution of sun heated

atmosphere through the motion of air• 2 types of air:

1. Warm air = Low pressure zone

2. Cold air = High pressure zone

• Transfer of air from

H L zones creates wind.

2. Ocean Currents

• Like rivers in the ocean:– Warm water from the equator to the poles– Cold water from the poles to the equator

3. Zones of Latitude

3 Zones:

1. Low/Tropical

2. Mid/Temperate

3. High/Polar

4. Elevation

• As altitude increases the temp. drops 3.5 degrees per 1000 ft.

• Climates above 12,000 ft. become like arctic areas.

5. Topography

• Landforms like mountains, affect climate• Rain shadow is an example:

Changes in Climate

• Are either due to:

1. Natural Causes 2. Human Activities

El Nino

• Warming of ocean waters off the west coast of S. America– Pushes warm waters

and heavy rains toward Americas

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Greenhouse Effect

• Layer of gasses created by the burning of fossil fuels, traps heated air.

Ch. 3.3 “World Climate Regions”

• Generalizations of typical weather conditions found in certain areas of the earth

• 2 biggest factors in determining regions:1. Temp.

2. Precipitation

12 Types of climate:

1. Tropical Wet:– Little temp. variation, typically hot, (around

80 degrees)

2. Tropical wet and dry:– Has both a wet (warm) and dry (cold)

seasons

3. Semiarid:– Little precip. about 16 in. per year.

4. Desert:– Categorized by amount of rainfall (lack of moisture),

not landforms

5. Mediterranean:– Dry hot summers, winters cool and rainy

6. Marine west coast: – Cloudy, foggy and damp and located close to the

ocean

7. Humid subtropical: – Summers hot and humid, winters are mild to cool

8. Humid continental:– Great variety in temp. and precipitation.

9. Subarctic: – Huge temp. variation between summer and winter

10. Tundra:– Flat treeless land almost exclusively in Northern

Hemisphere– Permafrost: soil is constantly frozen

11. Ice Cap: – Snow, ice, permanently frozen temp.

12. Highlands:– Climate varies with lat., elevation, topography

Ch. 3.4 “Soils and Vegetation”

• Soil: weathered rock, humus, air, water that covers the ground

• Depth, texture, humus content of soil determine the type of vegetation that can be supported– Temp and precipitation

also influence

Vegetation Regions

• Ecosystem: Interdependent community of plants and animals

• Biome: ecosystem of a region– 4 Types of Biomes:

1. Forest2. Grassland3. Desert4. Tundra

1. Forestlands

• Two Types:

2. Coniferous•Needleleaf•ie. pine

1. Deciduous• Broadleaf• ie. cottonwood

The Rain forest is located in the tropical zone; covered with broadleaf trees.

2. Grasslands

• Mostly flat dotted with a few trees.• Two types:

1. Savanna 2. Steppe or Praire• Northern Hemisphere

3. Desert

• Characterized by plants that can conserve water and withstand heat like:

Cactus Sagebrush

4. Tundra

• Characterized by plants that tolerate the cold and dry conditions by hugging the ground like:

Lichen Moss

Human Impact on Environment

Dams Crops