Download Global Climate Concepts

Global Climate Concepts
26 October 2016
Agenda
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Journal: FRQ
Answer FRQ
Notes: Climate Concepts
IP: Ocean & Air Current Maps
Objectives
• Explain how unequal heating of the earth
influences global climate.
• Diagram global air and ocean currents.
• Identify the major layers of the atmosphere.
• Describe how Earth’s tilt affects seasonal
differences in temperature.
The Unequal Heating of the Earth
• For this section:
– Identify the five layers of the atmosphere
– Discuss the factors that cause unequal heating of
the Earth
– Describe how the Earth’s tilt affects seasonal
differences in temperatures
Earth’s atmosphere is composed of layers
Atmospheric layers
• Layers get less dense as you get further from
earth
• Troposphere
– Closest to Earth’s surface
• Stratosphere
– Above the troposphere
– Contains ozone layer
• Mesosphere
• Thermosphere
• Exosphere
Solar Energy Reaching Earth Varies
• First cause of unequal warming of the earth is
variation in the angle at which the Sun’s rays
strike the earth.
• Sun’s rays hit the atmosphere at the equator
at a perpendicular angle, whereas in the poles
the Sun’s rays hit the atmosphere at an
oblique angle.
• Sun’s rays must travel a further distance to hit
the earth at the poles.
Solar Energy Reaching the Earth Varies
Solar Energy Reaching the Earth Varies
• Second cause of uneven warming is variation
in the amount of surface area over which the
Sun’s rays are distributed.
Solar Energy Reaching the Earth Varies
Solar Energy Reaching the Earth Varies
• Third cause of uneven warming is varying
albedo of earth’s surface.
• Albedo: The percentage of incoming sunlight
reflected from a surface
– White/light areas (polar ice caps, glaciers) reflect
more light back to the atmosphere than dark
areas (oceans)
Earth’s Tilt Causes Seasonal Changes in
Climate
• Earth tilts on its axis of rotation: 23.5°
Think-Pair-Share
• Which of the following is the correct order of
atmospheric layers starting from the Earth’s
surface?
A. Thermosphere, stratosphere, troposphere,
mesosphere, exosphere
B. Exosphere, troposphere, mesosphere, stratosphere,
thermosphere
C. Mesosphere, stratosphere, thermosphere,
exosphere, troposphere
D. Thermosphere, troposphere, stratosphere,
exosphere, mesosphere
E. Troposphere, stratosphere, mesosphere,
thermosphere, exosphere
Think-Pair-Share
• Which of the following is the correct order of
atmospheric layers starting from the Earth’s
surface?
A. Thermosphere, stratosphere, troposphere,
mesosphere, exosphere
B. Exosphere, troposphere, mesosphere, stratosphere,
thermosphere
C. Mesosphere, stratosphere, thermosphere,
exosphere, troposphere
D. Thermosphere, troposphere, stratosphere,
exosphere, mesosphere
E. Troposphere, stratosphere, mesosphere,
thermosphere, exosphere
Think-Pair-Share
• Which of the following contributes to the unequal
heating of the earth?
I. Variation in the angle of sunlight that reaches the
earth
II. Variation in the amount of surface area over which
the sun’s rays are distributed
III. Variation in the amount of sunlight reflected from
the clouds.
A. I only
B. I and II only
C. II and III only
D. III only
E. I, II, and III
Think-Pair-Share
• Which of the following contributes to the unequal
heating of the earth?
I. Variation in the angle of sunlight that reaches the
earth
II. Variation in the amount of surface area over which
the sun’s rays are distributed
III. Variation in the amount of sunlight reflected from
the clouds.
A. I only
B. I and II only
C. II and III only
D. III only
E. I, II, and III
Air Currents
• Explain how the properties of air affect the
way it moves in the atmosphere
• Identify the factors that drive atmospheric
convection currents
• Describe how the Earth’s rotation affects the
movement of air currents
• Explain how the movement of air currents
over mountain ranges affects climate
Properties of air
• 4 properties determine how air flows in the
atmosphere
– Density
– Water vapor capacity
– Adiabatic heating or cooling
– Latent heat release
Air density
• Density: the mass of all molecules in the air in
a given volume
• Less dense air rises
– Warm air has a lower density than cold air
• More dense air sinks
• Warm air rises
Water Vapor Capacity
• Water vapor capacity: the potential for an air
mass to hold moisture
• Warm air has the potential to hold more moisture
than cool air
• Saturation point: the maximum amount of water
vapor in the air at a given temperature
• When temperature of air falls, its saturation
point decreases, and water vapor condenses
into liquid water. Clouds form and precipitation
occurs.
Water Vapor Capacity
Adiabatic Cooling/Heating
• As air rises higher in the atmosphere, the
pressure on it decreases
• The lower pressure allows the rising air to expand
in volume, and this expansion lowers the
temperature of the air.
• This cooling effect is known as adiabatic cooling.
• When air sinks in the atmosphere, the opposite
occurs, and the temperature of the air rises.
• This heating effect is known as adiabatic heating.
Latent Heat Release
• Latent heat release: the release of energy
when water vapor in the atmosphere
condenses into liquid
• Whenever water vapor in the atmosphere
condenses, the air will become warmer and
rise in the atmosphere.
Atmospheric Convection Currents
• Atmospheric convection currents: global
patterns of air movement that are initiated by
the unequal heating of the earth.
• Warm, humid air rises, cools, and then sinks as
cooler, drier air.
Idealized Model of Convection
Currents
However, the earth is spinning
• The Coriolis effect, the deflection of an
object’s path due to the rotation of the Earth,
impacts these idealized cells
Model of Earth’s Climate Cells
(with prevailing wind directions)
Polar Cell
Ferrell Cell
Hadley Cell
Hadley Cell
Ferrell Cell
Polar Cell
Climate Cells
• Hadley cell: convection current in the atmosphere that
cycles between the equator and 30° N and 30°S
• Ferrell Cells: convection current in the atmosphere
that lies between the Hadley and Polar cells
• Polar Cells: Convection current in the atmosphere
formed by the air that rises at 60°N and 60°S and sinks
at 90°N and 90°S
• ITCZ: Intertropical convergence zone, the area at the
equator where the warm Hadley cell air rises and
precipitation falls.
– Characterized by dense clouds and intense
thunderstorms
Rain Shadow Effect
• Mountains cause air to be forced upward to
pass over them.
• As the air rises, its saturation point drops, and
it rains.
• This causes a dry region on the leeward size of
a mountain range as a result of humid winds
from the ocean causing precipitation of the
windward side.
Rain Shadow Effect
Think-Pair-Share
• Temperature change in adiabatic heating
occurs due to:
A.
B.
C.
D.
E.
Water vapor condensing
A pressure increase
Absorption of sunlight
A pressure decrease
A volume increase
Think-Pair-Share
• Temperature change in adiabatic heating
occurs due to:
A.
B.
C.
D.
E.
Water vapor condensing
A pressure increase
Absorption of sunlight
A pressure decrease
A volume increase
Think-Pair-Share
• Which is the correct order of the convection
cells, starting from the equator?
A. Polar, Ferrell, Hadley
B. Ferrell, Hadley, Polar
C. Polar, Hadley, Ferrell
D. Hadley, Ferrell, Polar
E. Hadley, Polar, Ferrell
Think-Pair-Share
• Which is the correct order of the convection
cells, starting from the equator?
A. Polar, Ferrell, Hadley
B. Ferrell, Hadley, Polar
C. Polar, Hadley, Ferrell
D. Hadley, Ferrell, Polar
E. Hadley, Polar, Ferrell
IP
• Given the map that is passed out
– Diagram the three atmospheric convection cells
– Do some research, and diagram the major ocean
currents