Climate & Vegetation Chapter 3

Earth-Sun Relationships Axis – imaginary line that run through the center of the Earth Earth’s axis is tilted 23 ½ ° Earth’s tilt affects the climate since all places do not receive the same amount of direct sunlight.

Earth-Sun Relationships Revolution – orbit around the sun Earth’s revolution takes 365 ¼ days. Revolution causes the changing seasons.

Earth-Sun Relationships Rotation – spinning on its axis The Earth’s rotation takes 24 hours. Rotation causes day and night.

Earth-Sun Relationships Equinox – either of the 2 times each year (spring and fall) when day and night are of nearly equal length everywhere on Earth Solstice – either of the 2 times a year (summer and winter) when the sun appears directly overhead at noon to observers at the Tropics of Cancer and Capricorn

Weather vs. Climate Weather - condition of the atmosphere at a particular location and time. Climate – the term for weather conditions at a particular location over a long period of time

Weather Extremes Hurricanes Tornadoes Blizzards Droughts Floods

Factors that Affect Climate Latitude – the amount of direct sunlight affects climate Places closer to the Equator receive more direct sunlight than areas closer to the poles which receive slanted rays.

Factors that Affect Climate Landforms – mountains can block precipitation which can affect climate. This is called the orographic effect (rain shadow). Ex. - Sierra Nevada range and the Mojave Desert Windward side – wet Leeward side - dry

Factors that Affect Climate Wind currents Prevailing winds are winds that blow in a fairly constant pattern. The direction of the winds can determine what type of weather patterns an area will see.

Factors that Affect Climate Ocean currents – cold and warm “rivers” of water known as currents, flow in the ocean Cold currents cool the lands they pass while warm currents have a warming effect. Ex. North Atlantic Drift flows near western Europe and gives the area a mild climate despite its northerly latitude

North Atlantic Drift

Factors that Affect Climate Proximity to large bodies of water Water is slower to heat and cool than land. Water temperatures are more constant and uniform than land temperatures. Temperatures of land areas located near oceans do not change as much as interior land areas.

Factors that Affect Climate Proximity to large bodies of water Example: City Newport, OR Rapid City, SD Location 44°N, 124°W 44°N, 103°W Average Jan. 44° F Jan. 22° F Temperatures July 57° F July 72° F

Factors that Affect Climate Elevation – for every 1,000 feet gained, the temperature drops about 3.5° F. Mt. Kilimanjaro in Africa is located near the Equator, but is covered with snow and ice

Changes in Climate El Nino – warming of the waters off the west coast of South America About every 7 years, prevailing easterly winds that blow over the central Pacific Ocean slow or reverse direction The winds push warm ocean water toward the Americas causing floods and mudslides, Australia and Asia experience drought conditions The reverse is called La Nina – this causes an increase in precipitation in places such as India and dryness along the Pacific coast of the Americas

Changes in Climate Global Warming – although controversy exists over the causes of global warming, scientists agree temperatures are increasing Some believe the cause is the greenhouse effect – layer of gases released by burning of coal and petroleum traps some solar energy, causing higher temperatures Scientist predict that, if global warming continues, ice caps will melt, flooding some coastal areas, covering islands, and changing the global climate

5 Major Climate Regions Tropical Dry Mid-Latitude High-Latitude Highlands See pages 60-61

Types of Precipitation Convectional –hot, humid air rises and cools losing its ability to hold water (ex. Tropical rainforest) Orographic – warm moist air is forced up when passing over high landforms Frontal – 2 fronts of different temperatures meet

Convectional Precipitation

Frontal Precipitation

Orographic Precipitation

Four Types of Vegetation Forest Grassland Desert Tundra

Forest Tropical rainforest Deciduous forest – broadleaf, such as maple and oak Coniferous forest – cone bearing, evergreens Chaparral

Forest

Grassland Tropical grasslands (savannas) Temperate grasslands (prairies, steppes, pampas)

Grasslands

Desert A desert can occur where there is a lack of precipitation, less than 10 inches a year. Deserts can be cold, they do not have to be hot and sandy. Vegetation – plants that can conserve water & withstand heat such as cacti & sagebrush

Desert

Tundra Alpine tundra Arctic tundra Vegetation – includes mosses & lichens Anaktuvuk Pass, Alaska