splash screen. section 1-gtr earth-sun relationships how does earth’s position in relation to the...
TRANSCRIPT
Splash Screen
Earth-Sun Relationships
How does Earth’s position in relation to the sun affect life on Earth?
• weather
Earth-Sun Relationships
• equinox• solstice• greenhouse effect • global warming
• climate • axis• temperature• revolution
• contrast
Earth-Sun Relationships
• affects • regulated
The relationship between the Earth and the sun affects climate, which influences life on Earth in dramatic ways.
Climate and Weather
• Earth’s tilt is one reason for variations in sunlight.
• The angle of tilt affects the temperature, which is measured in Fahrenheit or Celsius.
• Earth rotates on its axis, making one complete rotation from west to east every 24 hours.
• While Earth is rotating on its axis, it is also traveling in an orbit around the sun—this revolution takes 365 days to complete.
• The Earth’s revolution and tilt cause changes in the angle and amount of sunlight that reach different locations on the planet, also known as seasons.
Climate and Weather (cont.)
Effects of Earth’s Tilt
Climate and Weather (cont.)
• The Tropics of Cancer and Capricorn
– When the sun’s rays directly strike the Tropic of Cancer, this marks the beginning of summer in the Northern Hemisphere.
– When the sun’s rays directly strike the Tropic of Capricorn, this marks the beginning of winter in the Northern Hemisphere.
Climate and Weather (cont.)
• The Poles
– At the North Pole, the sun never sets from about March 20 to September 23.
– At the South Pole, the sun never sets from about September 23 to March 20.
The Earth’s Seasons
The natural process of the greenhouse effect has been influenced by human activity.
The Greenhouse Effect
• Like the glass in a greenhouse, the atmosphere traps some heat and keeps it from escaping back into space too quickly so that the Earth is warm enough to maintain life.
The Greenhouse Effect (cont.)
• Many scientists claim that in recent decades a rise in atmospheric carbon dioxide levels has coincided with a general rise in global temperatures, also known as global warming.
The Greenhouse Effect
A. A
B. B
C. C
D. D A B C D
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Which of the following do you think has caused global warming?
A. A natural cycle
B. Human activity
C. Both
D. Neither
Factors Affecting Climate
What factors can affect how climates are distributed on Earth’s surface?
• prevailing wind
Factors Affecting Climate
• El Niño • windward • leeward • rain shadow effect
• retains
• Coriolis effect• doldrums • current
• creates
• factors
A. low latitudes
Factors Affecting Climate
B. high latitudes
C. Arctic Circle
D. Antarctic Circle
E. midlatitudes
Latitude and elevation affect the angle of the sun’s rays and temperatures on Earth.
Latitude, Elevation, and Climate
• Low latitudes include the Tropic of Capricorn, the Equator, and the Tropic of Cancer.
• The Earth’s polar areas are considered the high latitudes.
Latitude, Elevation, and Climate (cont.)
• Midlatitudes:
– Between 30 degrees N and 60 degrees N in the Northern Hemisphere, and between 30 degrees S and 60 degrees S in the Southern Hemisphere, are considered the midlatitudes.
– The most variable weather is found here.
Latitude, Elevation, and Climate (cont.)
• Elevation:
– At all latitudes, elevation influences climate because of the relationship between the elevation of a place and its temperature.
– As elevation increases, temperature decreases.
The Influence of Elevation on Temperature
Wind and water combine with the effects of the sun to influence Earth’s weather and climate.
Winds and Ocean Currents
• Wind Patterns:
– Wind blows because of temperature differences on Earth’s surface, with tropical air moving toward the Poles and polar air moving toward the Equator.
Winds and Ocean Currents (cont.)
– Global winds blow in fairly constant patterns called prevailing winds.
– The Coriolis effect causes prevailing winds to blow diagonally rather than along strict north-south or east-west directions.
World Zones of Latitude and Wind Patterns
Winds and Ocean Currents (cont.)
• The Horse Latitudes:
– When sailors became stranded in the doldrums, they would lighten the load of the ships, including livestock, so that a light breeze could move them.
– These areas then became known as the horse latitudes.
Winds and Ocean Currents (cont.)
• Ocean currents are caused by factors such as:
– the Earth’s rotation
– changes in air pressure
– differences in water temperature
• The Coriolis effect is observed in ocean currents as well.
• Ocean currents affect climate in the coastal lands along which they flow.
World Ocean Currents
Winds and Ocean Currents (cont.)
• Weather and Water Cycle
– Wind and water work together to affect weather—driven by temperature, condensation creates precipitation
• El Niño can influence climates around the world.
The Influence of El Niño
Landforms and bodies of water influence Earth’s climate patterns.
Landforms and Climate
• The climate of places located at the same latitude can be very different, depending on the presence or absence of certain physical features.
• Coastal areas tend to have less changeable weather than do inland areas.
• Mountain ranges have varying weather, depending on the area of the mountain.
The Rain Shadow Effect
A. A
B. B
Which side of the mountain is drier than the other side?
A. Windward
B. Leeward
A B
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World Climate Patterns
How do geographers classify Earth’s climate and vegetation?
• natural vegetation
World Climate Patterns
• mixed forest• prairie• permafrost• hypothesis• smog
• widespread
• oasis• coniferous• deciduous
• exceeds
• consists
Geographers divide the Earth into regions that have similar climates.
Climate Regions
• Each of these divisions has its own characteristic soils and natural vegetation.
Latitude, Climate, and Vegetation
Climate Regions (cont.)
• Climates are organized into five regions:
– Tropical climates—these are found in or near the low latitudes—the Tropics.
• Tropical wet
• Tropical dry
Climate Regions (cont.)
– Dry climates—there are two types of dry climates—the desert and the steppe—which occur in low latitudes or midlatitudes.
– Midlatitude climates—this climate experiences variable weather patterns and season changes that give rise to a variety of natural vegetation.
World Climate Regions
Climate Regions (cont.)
• There are four temperate climate regions:
– Marine west coast climate
– Mediterranean
– Humid subtropical
– Humid continental
Climate Regions (cont.)
• High altitude climates—freezing temperatures are common throughout the year because of the lack of direct sunlight.
• Three high altitude climate regions are:
– Subarctic
– Tundra
– Ice cap
Climate Regions (cont.)
• Highland climates—high mountain areas, even along the Equator, share some of the same characteristics because of the thinning of the atmosphere at high altitudes.
World Natural Vegetation Regions
A. A
B. B
C. C
D. DA B
C
D
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Which type of climate is the least arid?
A. Tundra
B. Desert
C. Rain forest
D. Mixed forest
Climate changes over time. Although the causes of change are unclear, evidence suggests that human activity has influenced some of the changes.
Climate Changes
• Burning fossil fuels releases gases that mix with water in the air, forming acids that fall in rain and snow.
• This act can cause many changes in climate.
A. A
B. B
C. C
Do you agree that humans are altering the climate?
A. Strongly agree
B. Somewhat agree
C. Do not agree
A B
C
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