1. Climate and Vegetation
Chapter 3
Climate and Vegetation

2. Seasons and Weather
Seasons and weather occur because of the changing position of the earth.
Weather extremes are related to location on the earth.

3. Seasons The earths tilt affects seasonal changes Equinox
Sun S
The earths tilt affects seasonal changes
The earth is tilted on its axis at 23.5° in relation to the sun.
Solstice
Day on which the Earth is at it fullest tilt towards and away from the sun.
Longest day (start of summer) and shortest day (start of winter) of the year.
Tropic of Cancer and Tropic of Capricorn will receive direct sunlight
Equinox
The equator receives direct sunlight creating equal day and night around the planet
Spring Equinox and Fall Equinox

4. Weather
Weather is the particular condition of the atmosphere at a specific time in a specific area.
Weather is affected by:
Humidity - amount of water vapor in the air
Landforms and Bodies of water - Oceans, lakes, swamps, etc…
Water heats and cools slowly, land heats quickly but also loses heat slowly
Elevation - the higher in the atmosphere, the less moisture the air can hold
Air movement - winds and solar energy creating fronts, jet stream, pressure systems.

5. Weather (pg 50) Precipitation
water that falls from the atmosphere as either rain, sleet snow or hail.
Convectional- result from moist air being heated by the daily sun causing air to rise, as the sun descends the air cools off and rains.
Orographic- as a mass of air moves over land, the rise in land elevation causes the air to move up. When moisture rises into thinner air the air can no longer hold the moisture and precipitation falls.
The region immediately beyond the higher elevation becomes extremely dry, as the air is basically a squeezed out sponge, creates an arid environment called a rain shadow.
Frontal- when a warm air mass (front) meets a cooler air mass, the warmer air will be pushed over the cooler and result in rain.

6. Weather Extremes Hurricanes Tornadoes
weather system that forms over warm water that consists of high winds (excess of 74mph), high storm surge (can be more than 25 ft), and flooding rains.
Also known as Typhoons in Asia and cyclones in in Australia
can take days to develop
Tornadoes
A tightly spun, spiraling column of air around a low pressure center. Winds can reach an excess of 300 mph and can be up to a mile or more wide.
Can form instantly with no warning
Can reach speeds of 300+ mph Among the most destructive forces on the planet.

7. Blizzards Droughts Floods
Heavy snowstorm with winds in excess of 35mph and greatly increased snowfall and reduced visibility.
Creates road hazards, building structures to collapse, power failures, endangers livestock.
Droughts
An extended period of time with little to no rainfall.
Large areas often experience dust storms which can cause widespread damage to transportation and all machinery caught in these “storms paths
Results in crop failures among other problems.
Floods
Can be caused by sudden downpours and snowmelt in an area not ready to receive the sudden amount
Sudden heavy rainfall in areas with a saturated ground or are in a low-lying area with streams or rivers.

8. Climate
Climate is the weather conditions of a place over an extended period of time.
Temperature and Amount of Precipitation are used to determine climate
Global climatic changes may be caused naturally or can be man-made

9. Factors affecting climate…
Wind currents
Warmer air moves towards the poles while cooler air moves towards equator distributing the sun’s heat (convection)
Since the earth is rotating the air does not go up and sink at the same location, instead it moves at an angle.
globally air moves from the heated equatorial regions toward the polar regions.
This bending of the wind is created by the Coriolis Effect
Global wind currents are listed on Pg 54
North- and Southeasterly Trade winds, Westerlies, and the Polar Easterlies
Ocean Currents
Warm water rising, cooler water sinking.
Warm flows away from Equator toward poles, cool water flows toward Equator from poles.
Winds blowing over ocean currents

10. Factors of climate Ocean Currents Zones of Latitude
Behave similar to wind currents through convection
Create “rivers” within the oceans that make a circular pattern of warm water carried to the poles and cooler water toward the equator
Affects temperature and precipitation
Zones of Latitude
Equator receives the most direct sunlight, therefore it is hotter. Therefore, as you move outward toward the poles the air becomes cooler.
Divided into three levels defined by the Tropic of Capricorn (southern hemisphere) and the Tropic of Cancer (northern hemisphere)
Low or tropical latitudes
Middle or temperate latitudes
High or polar latitudes

11. Factors of climate Elevation Topography
Air becomes thinner as it rises higher in elevation, because of this the air mass can no longer hold as much moisture
Temperatures in higher elevations are less affected by latitude.
Mt. Kilimijaro (Tanzania, Africa) is on the equator , but has a permanent ice cap
Topography
Landforms, such as mountain and highlands, can trap moisture as well as block moisture from reaching into other areas
As air moves over land that is gaining in elevation, the mass will be squeezed and moisture will be released.
Moisture will only climb in altitude as much as the air holding it can carry, once it reaches a certain altitude it can no longer be transported, thus precipitation occurs.
When the air mass is not able to carry the moisture over higher elevated landforms the air mass will move over but the moisture will not causing a Rain Shadow on the other side.
Rain shadows are regions on the leeward side of mountains that receive little to no precipitation, usually a dry environment.

12. Changes in Climate El Nino and La Nina
El Nino occurs when the waters off the north eastern coast of South America begin to warm up causing the wind patterns to temporarily reverse from blowing towards Asia and Australia to blow towards the Americas
This occurs every 2 to 7 years
As winds blow over this warmer water climates shift worldwide
La Nina occurs when the same waters become cooler causing the air to reverse El Nino wind patterns back to east to west towards the western Pacific Rim continents.

13. Changes in Climate Global warming
The earth has cycles of heating and cooling
When heating occurs glacial ice will melt causing water levels to rise globally resulting in warmer climates.
The Greenhouse Effect states that certain gases that are trapped in our atmosphere do not escape the earth’s atmosphere, causing the global temperature to climb.
Controversy surrounds this issue as a result of an environmental movement against certain types of industrial growth that use many nonrenewable resources for energy.
The argument is industries that burn coal, petroleum and other resources, create harmful gases that retain heat as well as block heat from escaping the earth’s atmosphere
Scientist are on both sides of the issue

14. World Climate Regions See page 60-62
Temperature and amount of precipitaion create climates
Location on a continent, topography and altitude affect climate as well.
Types of Climate Regions
Tropical Wet
Tropical Wet and Dry
Semiarid
Desert
Mediterranean
Marine West Coast
Humid Subtropical
Humid Continental
Subarctic
Tundra
Ice Cap
Highlands
See page 60-62

15. Soils and Vegetation Soil regions
The majority of all life on the planet depends on the top 6 inches of soil.
Some areas have deeper topsoil than others
Topsoil depth affects the ability of plants to take root.
Soil composition (Chapter 2) is different in all parts of the globe
Depth and type of soil affect the type of vegetation grown in a region

16. Soils and Vegetation Vegetation Regions Ecosystems Biomes
An interdependent community of plants and animals.
Biomes
An ecosystem in a specific region.
Divided into forestland, grassland, desert, and tundra.

17. Vegetation Regions Forestlands Categorized two types of trees
Broadleaf
Also called Deciduous
Birch and cottonwood
Needleleaf
Also called Coniferous (cone-bearing)
Pine, Fir and Cedar
Tropical Rainforest, Temperate Rainforests, Deciduous and Pine forests, and Mixed Forests.

18. Vegetation Regions Grasslands Tropical grasslands Temperate Grasslands
Known as Savanna
Located along the tropic or low latitudes
Sparsely dotted with trees
Think of “The Lion King”
Temperate Grasslands
Known as prairies, steppes, or pampas.
Located in the temperate or middle latitudes
Dotted with trees more than savanna
Think of the Great Plains

19. Vegetation Regions Desert Located anywhere there is a rain shadow
Average rainfall is less than 1.5 feet of rain a year
Vegetation is dependent on very little rainfall and has ability to store water for extended periods of time.
An extremely fragile biome
everything thing that lives in this environment is dependent on everything else in this environment.
Can be located anywhere on the planet
some are cold and some are hot.

20. Vegetation Regions Tundra
Mostly located above the Arctic Circle and below the Antarctic circle, but can be found in higher elevations
Ground is frozen limiting and often preventing seed germination and plant growth leaving only small shrubs and plants, otherwise treeless.
Permafrost is permanently frozen ground.