Download 26.1 Factors That Affect Climate climate

Climate
Chapter 26
Modern Earth Science
26.1 Factors That Affect Climate
climate the average weather conditions in an area
over a long period of time
 Temperature Range: the difference between the
highest and lowest temperatures of a month
 Precipitation: The average amount of rainfall an
area can acquire over a year
 The climate of a region can also be affected by the
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Latitude of a region
Heat absorption and release
Topography
Winds
Ocean currents
Latitude
 Latitude is the distance from
the equator.
 Latitude determines the amount of
solar energy received, and the
prevailing winds of a region
 The higher the latitude of an area
is, the smaller the angle at which
the sun’s rays hit Earth is and the
smaller the amount of solar
energy received by the area is.
Solar Energy
 Because Earth’s axis is tilted, the angle at
which the sun’s rays hit an area changes as
Earth orbits the sun.
 Equatorial regions: 12 hours day & night
with steady high temperatures.
 Polar regions: large variation of daylight
hours, steady low temperatures.
Wind Patterns
 Latitude determines global
winds
 Winds affect humidity,
precipitation, temperature, &
cloud cover.
 Different prevailing winds =
different climate
 Global winds also affected by
ocean currents & major
mountain ranges.
Heat Absorption & Release
specific heat the quantity of heat required to
raise the temperature of 1 gram of a
substance 1°C
 Even if not in motion, water warms more
slowly than land does.
 Water also releases heat energy more
slowly than land does.
Heat Absorption & Release 2
 Land heats faster than water and thus can reach
higher temperatures in the same amount of time.
 Waves, currents, and other movements
continuously replace warm surface water with
cooler water from the ocean depths.
 In turn, the temperature of the land or ocean
influences the amount of heat that the air above
the land or ocean absorbs or releases.
 The temperature of the air then affects the climate
of the area.
Ocean Currents
 Water moves around the globe – LAND DOESN’T
 The temperature of ocean currents that come in
contact with the air influences the amount of heat
absorbed or released by the air.
 The temperature of the air moving ONTO SHORE
is affected by the temperature of the ocean/water it
comes into contact with
Seasonal Winds
monsoon a seasonal wind that blows toward the
land in the summer, bringing heavy rains, and that
blows away from the land in the winter, bringing
dry weather
 Temperature differences between the land and the
oceans sometimes cause winds to shift seasonally
in some regions.
 Monsoon climates, such as that in southern Asia,
are caused by heating and cooling of the northern
Indian peninsula.
Topography
Elevation
 The surface features of the land, or topography,
also influences climate.
 The elevation, or height of landforms above sea
level, produces distinct temperature changes.
 Temperature generally decreases as elevation
increases.
More Topography
Rain Shadows
 When a moving air mass encounters a mountain
range, the air mass rises, cools, and loses most of
its moisture through precipitation.
 As a result, the air that flows down the other side
of the range is usually warm and dry. This effect is
called a rain shadow.
 One type of warm, dry wind that forms in this way
is a foehn (FAYN), a dry wind that flows down the
slopes of the Alps.
26.2 Climate Zones
Climate Zones
 3 Major Climate Zones
– Polar Climate
– Middle-latitude Climate
– Tropical Climate
Tropical Climate
 3 Tropical Climates
– Desert
– Rain Forest
– Savanna
Desert
Tropical
Rain
Forest
Savanna
Polar Climate
 2 Polar Climates
Subarctic
Polar
– Subarctic
 Severe winters & short
summers
 Canada
– Tundra
 No trees, very dry, cold
air with little precipitation
 Northern Alaska
Tundra
Middle-Latitude Climate
 5 Climates
– Desert & Steppe
 Eastern Montana
– Mediterranean
 Most of California
Desert &
Steppe
– Marine West-Coast
 Seattle
– Humid Sub-tropical
 Georgia
Humid
Sub-tropical
Mediterranean
MiddleLatitude
– Humid Continental
 Iowa
Humid
Continental
Marine
West-Coast
US: The Middle Latitude Climate
Marine West Coast Climate
Mediterranean
Middle Latitude Steppe
Middle Latitude Desert
Humid Continental
Humid Subtropical
Tropical Rain Forest
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Warm & humid
Near the equator (5 - 10° north & south)
Dense, rain-forest vegetation
Annual rainfall more than 250 cm
Yearly temp. range only about 3° C
Amazon River basin, parts of Central
America & Southeast Asia
Tropical Desert
Tropical Savanna
Polar Climates
Subarctic
Tundra
Middle-Latitude Climates