Download Chapter 22 - Science at Spectrum

Lesson 4 –
Radiation
Shuttle Takeoff 11:31
Recovery of boosters
11:40
 All of the energy that Earth receives from the sun travels
through space as radiation.
 Radiation is the transfer of heat energy without the
involvement of a physical substance in the transmission.
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Radiation
 Electromagnetic spectrum refers to all of the frequencies or
wavelengths of electromagnetic radiation.
 The various types of radiation differ in the length of their
wavelength and the amount of energy carried within their
wavelength.
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Radiation
 Electromagnetic radiation can be described in terms of a
stream of photons, which are mass-less particles each traveling
in a wave-like pattern and moving at the speed of light.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Radiation
 Each photon contains a certain amount (or bundle) of energy.
 The only difference between the various radiation is the
amount of energy found in the photons.
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Radiation
 Any type of electromagnetic energy can be transformed into
thermal energy.
 Thus, any electromagnetic radiation can "heat" a material
when it is absorbed.
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 If we were to compare water flow to the electromagnetic
spectrum, radio waves & microwaves would be
comparable to a mist of water.
Radiation
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 The photons that create infrared, visible light and ultraviolet
radiation would be comparable to a water hose of water.
Radiation
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 X-rays and gamma-ray radiation would be comparable to a
fire hose of water.
Radiation
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 All of the high-energy
Gamma rays, X-rays
and high energy UV
radiation are absorbed
by our atmosphere
well above our heads.
 What we receive in the
troposphere is:
 the low energy UV
radiation,
 visible light and
 short wave Infrared
along with longer wave
radio waves.
Radiation
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Essentially 100% of the
energy that fuels the earth
comes from the sun.
 To maintain a constant
global average temperature,
all of the sun’s radiation that
enters Earth’s atmosphere
must eventually be sent
back to space.
 This is achieved through
Earth’s energy balance.
Energy Heat Transfer
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 There are three
ways energy can
be transferred
between the
earth's surface
and the
atmosphere:
 1) Convection
 2) Conduction
 3) Radiation.
Energy Heat Transfer
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Convection
 Convection is heat transfer by the movement of mass from one
place to another.
 In the atmosphere, convection includes large- and small-scale
rising and sinking of air masses and smaller air parcels.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Conduction
 Conduction is the transfer of energy as heat from one
substance to another by direct contact with matter.
 Since air is a poor conductor, most energy transfer by
conduction occurs right at the earth's surface.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 During the day, solar
radiation heats the
ground, which heats
the air next to it by
conduction.
Explaining
Conduction
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 At night, the ground
cools and the colder
ground cools the air
around it by
conduction
(sometimes cool
enough to create a
fog).
Conduction
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Lesson 5Absorption
and Infrared
Energy
sound of take off 3:50
Shuttle Landing 8:00
 Of all the sunlight that passes through the atmosphere
annually, only about 50% is available at the Earth's surface
to do work.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 This 50% of energy
is used to:
 Heat the Earth's
surface and lower
atmosphere,
 Melt and evaporate
water
 Run photosynthesis
in plants.
Absorption and
Infrared Energy
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Absorption
and Infrared
Energy
 Of the other approx. 50%:
 4% is reflected back to space by the Earth's surface
 26% is scattered or reflected to space by clouds and
atmospheric particles
 19% is absorbed by atmospheric gases, particles, and
clouds.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 There are three
atmospheric processes
that can modify the solar
radiation passing through
our atmosphere destined
to the Earth's surface.
 1) Absorbtion
 2) Scattering
 3) Reflection
The Atmosphere
and Solar Radiation
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Absorption is
defined as a process
in which solar
radiation is retained
by a substance and
converted into heat
energy.
Absorption
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Scattering
 The process of scattering occurs when solar radiation is sent
in random directions without any change to the wavelength of
the electromagnetic energy.
 Scattering does reduce the amount of incoming radiation
reaching the Earth's surface.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Reflection is a process
where sunlight is
redirect by 180° after it
strikes an atmospheric
particle.
 In this process, the solar
radiation striking an
atmospheric particle is
redirected back to space
unchanged.
Reflection
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Most of the
reflection in our
atmosphere occurs
in clouds when light
is intercepted by
particles of liquid
and frozen water.
Reflection
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Reflectivity of the surface is
often described by the
term surface albedo.
 The Earth's average albedo,
reflectance from both the
atmosphere and the surface,
is about 30%.
Albedo Effect
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 The reflectivity or
albedo of the
Earth's surface
varies with the
type of material
that covers it.
 For example,
fresh snow can
reflect up to 95%
of the insulation
that reaches it
surface.
Albedo Effect
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 The greenhouse effect
refers to process where
visible light energy from
the sun pass through glass
or our atmosphere and is
absorbed but the infra-red
heat energy created from
the ground because
trapped by the glass or our
atmosphere.
The Greenhouse
Effect
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Frosty the Snowman
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Greenhouse
Effect
 This greenhouse effect occurs because light is a shorter
wavelength.
 When light energy is absorbed it is turned into infra-red
energy which has a longer wavelength and can no longer
escape the way it entered.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Bright sunlight will
effectively warm your car
on a cold, clear day by
the greenhouse effect.
The Greenhouse
Effect in a car
 The longer infrared
wavelengths radiated by
sun-warmed objects do
not pass readily through
the glass.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 The entrapment of this
energy warms the
interior of the vehicle
making it very
uncomfortable to enter
are stay in.
The Greenhouse
Effect in a car
 The greenhouse effect
has been widely used to
describe the trapping of
excess heat by the rising
concentration of carbon
dioxide in the
atmosphere.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Lesson 6 – Atmospheric Circulation
 Pressure differences in the atmosphere cause the
movement of air worldwide.
 The air near Earth’s surface generally flows from the
poles toward the equator and this is because cold air
sinks (forming a high pressure) and wants to replace
the hotter (lower pressure) air.
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 As the air circulates it
is affected by another
factor the Coriolis
effect.
 The Coriolis effect is a
force acting on winds
causing them to curve
because the Earth is
spinning.
Coriolis Effect
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Each hemisphere contains
three looping patterns of
flow called convection
cells.
 Each convection cell
correlates to an area of
Earth’s surface, called a
wind belt, that is
characterized by winds
that flow in one direction.
Global Winds
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Three Types
of Prevailing
Winds
 These wind belts are called prevailing winds.




There are three types of prevailing winds:
1) Trade Winds
2) Westerlies
3) Polar Easterlies
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Named from their ability to
quickly propel trading
ships across the ocean,
the trade winds between
about 30° latitude and the
equator are steady and
blow about 11 to 13 miles
per hour in both
hemispheres.
Trade Winds –
Equatorial winds
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 In the Northern
Hemisphere, the trade
winds flow the northeast
and are called the
northeast trade winds.
 In the Southern
Hemisphere, they are the
southeast trade winds.
Trade Winds –
Equatorial winds
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Westerlies are
prevailing winds that
blow from west to east
between 30º and 60º
latitude in both
hemispheres.
Westerlies
 Between 30º and 60º
latitude, some of the
descending air moving
toward the poles is
deflected by the Coriolis
effect.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 In the Northern
Hemisphere, the
westerlies are the
southwest winds.
 In the Southern
Hemisphere, they are
the northwest winds.
Westerlies
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Polar Easterlies prevailing
winds that blow from east to
west between 60° and 90°
latitude in both hemispheres
 Surface winds created by
the polar high pressure are
deflected by the Coriolis
effect and become the polar
easterlies.
Polar Easterlies
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Sailors noticed the
stillness of the rising
(and not blowing) air
near the equator and
gave the region the
depressing name
"doldrums."
Doldrums
 The doldrums, are
located between 5° north
and 5° south of the
equator.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 In this warm zone, most
air movement is upward
and produces some of
the world's heaviest
precipitation regions
including the Amazon
Forest.
Doldrums
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Horse latitudes are
two belts of latitude
where winds are light
and the weather is
hot and dry.
 They are located at
about 30° latitude and
create some of the
great deserts on
Earth including Death
Valley.
Horse Latitudes
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 This occurs because air
is an area can go either
way - as part of the
prevailing trade winds or
toward the poles as part
of the Westerlies.
 Ships in the horse
latitudes would often
become be-calmed in
mid-ocean, thus
severely prolonging the
voyage.
Horse Latitudes
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Wind and
Pressure
Shifts
fires
fires2
fires3
 As the sun’s rays shift northward and southward during the
changing seasons of the year, the positions of the pressure
belts and wind belts shift.
 This small change causes some areas of Earth’s surface to be
in different wind belts during different times of the year.
Chapter 22
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 Jet Streams are a narrow
band of strong winds that
blow in the upper
troposphere.
 These winds exist in the
Northern and Southern
Hemisphere.
Jet Stream
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
 There are two major jet
streams: polar jet streams and
the higher and weaker
subtropical jet streams.
 The wind speeds vary
according to the
temperature gradient, but
typically measure anywhere
from 50 mph on up to
250 mph.
Jet Stream
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
Jet Stream
 They are important because they affect the path of storms
and airline routes.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
California’s Place
in the
Atmosphere
 California is located in the northern hemisphere above
30°N latitude.
 This puts California within the prevailing westerlies wind
belt.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights
California’s Place
in the
Atmosphere
 Winds generally blow from the west, off the Pacific Ocean,
to the east.
Chapter menu
Resources
Copyright © by Holt, Rinehart and Winston. All rights