Transcript Factors that Affect Climate

Video Field Trip: Polar Weather
Take a field trip to the North and South
Poles with Discovery Channel. Answer
the following questions after watching the
video.
1. Why is Antarctica technically called a
desert?
2. What would happen to the ocean if the
ice shelves around Antarctica melted?
Factors that Affect Climate
Chapter 21, Section 1
Latitude
• As latitude increases, the intensity of solar
energy decreases
• Near the equator, the sun’s energy strikes the
planet at nearly right angles, therefore the sun’s
ray’s are more intense here
• Tropical Zone – region between 23.5º north and
23.5º south of the equator; sun’s rays are most
intense; generally warm year-round
• Temperate Zone – region located between
23.5º and 66.5º north and south of the equator;
sun’s rays strike Earth at a smaller angle; hot
summers and cold winters
• Polar Zone – the region between 66.5º north
and south of the equator and the poles; sun’s
rays strike at a very low angle; experience cold
temperatures year-round
Concept Check
• Compare and contrast tropical zones,
temperate zones, and polar zones in terms
of location and the intensity of solar
radiation that each receives.
Elevation
• Air temperature decreases with elevation
by an average of ~6.5º every 1000 meters
• The higher the elevation is, the colder the
climate
• The elevation of an area also determines
the amount of precipitation it receives
Influence of
Elevation on
Climate
Concept Check
• How does elevation affect climate?
• The higher the elevation, the colder the air
and therefore, the colder the climate.
Topography
• Topographic features such as mountains
play an important role in the amount of
precipitation that falls over an area
• Heavy precipitation often falls on the
windward side of mountains
• By the time the air reaches the leeward
side, much of the moisture is lost (rain
shadow)
• Rain shadows can extend for hundreds of
kilometers downwind of a mountain range
The Rain Shadow Effect
Concept Check
• How does a mountain range affect
climate?
• Windward side: humid air moves up the
mountain’s slopes and cools to form
clouds that produce precipitation.
• Leeward side: the air is warm and very
dry.
Water Bodies
• Large bodies of water such as lakes and
oceans have an important effect on the
temperature of an area because the
temperature of the water body influences
the temperature of the air above it
• Places downwind of a large body of water
generally have cooler summers and milder
winters than places at the same latitude
that are farther inland
Concept Check
• How do large bodies of water affect
climate?
• Places downwind of a large body of water
generally have milder seasons than places
farther inland at the same latitude.
Atmospheric Circulation
• Global winds are another factor that
influences climate because they distribute
heat and moisture around Earth
• Winds are constantly moving warm air
toward the poles and cool air toward the
equator
• The low-pressure zones at the equator
and subpolar regions lead to the formation
of clouds and precipitation
Atmospheric Circulation
Concept Check
• What effect do global winds have on
climate?
• They move heat and moisture around
Earth.
Vegetation
• The types of plants that grow in a region
depend on climate and affect climate
• Vegetation can affect both temperature
and precipitation patterns in an area
• Vegetation influences how much of the
sun’s energy is absorbed and how quickly
this energy is released (influences
temperature)
• During a process called transpiration,
plants release water vapor from their
leaves into the air (influences precipitation)
Concept Check
• Describe different ways in which
vegetation affects climate.
• It influences how much of the sun’s energy
is absorbed and released, thereby
affecting temperature. Plants release
water vapor and influence regional
precipitation patterns.
Assignment
• Read Chapter 21, Section 1 (pg. 588-591)
• Do Chapter 21 Assessment #1-32 (pg. 609610)