The Earth’s Global Energy Balance Geography 3

1. CHAPTER II :
The Earth’s
Global Energy
Balance
Prepared by: Byron John Meneses

2. TOPICS TO BE DISCUSSED
 Sensible Heat and Latent
Heat Transfer (pg. 49)
 The Global Energy System
(pg. 50)
 Net Radiation, Latitude, and
the Energy Balance (pg. 56)
 Electromagnetic Radiation
(pg.36)
 Insolation over the Globe
(pg.42)
 Composition of the
Atmosphere (pg.46)
2

3. ELECTROMAGNETIC RADIATION
Electromagnetic radiation Wave-like form of energy radiated
by any sub-stance possessing heat; it travels through space
at the
speed of light.
3

4. Light and heat are both forms of electromagnetic
radiation. You can think of electromagnetic radiation
as a collection of waves, of a wide range of
wavelengths,
that travel away from the surface of an object.
Radiant
energy can exist at any wavelength. Heat and light
are
identical forms of electromagnetic radiation except
4

5. Wavelengths
- is the distance
separating one wave crest from
the next wave crest

6. TYPES OF
ELECTROMAGN
ETIC RADIATION

7. ➢ Very hot objects, such as the Sun or a light bulb
filament
➢ ultraviolet and infrared light that cannot be seen.
➢ the fiery Sun in thesky to the skin covering our
bodies
7

8. RADIATION
AND
TEMPERATUR
E
• SOLAR RADIATION
• CHARACTERISTICS OF
SOLAR ENERGY
8

9. hot objects radiate much
more energy
than cooler objects.
PRINCIPLES OF RADIATION AND TEMPERATURE
the hotter the object,
the shorter are the
wavelengths of radiation that
it
emits
9

10. CHARACTERISTICS OF SOLAR ENERGY
Molecules and particles in
the atmosphere intercept and
absorb radiation at particular
wavelengths. This atmospheric
absorption directly warms the
atmosphere in a way that affects
the global energy balance, as we
will discuss toward the end of
this chapter.
Solar rays can also be scattered
into different directions when they
collide with molecules or particles
in the atmosphere. Rays can be
diverted back up into space or
down toward the surface.
10

11. “
https://www.youtube.c
om/watch?v=gS2_1pe
zW_Y
11

12. The Earth emits longwave
radiation Shortwave radiation is
absorbed by the Earth and the
atmosphere, increasing earthly
temperatures and generating
longwave radiation that radiates
back to space.
12

13. 13
Insolation
over the
Globe

14. What is Insolation?
14
Insolation is the flow of solar energy intercepted by an ex-posed
surface assuming a uniformly spherical Earth with no
atmosphere.

15. 89,526,124
Whoa! That’s a big number, aren’t you proud?
15

16. How does the angle of the Sun
vary during the day?
16
It depends on the Sun’s path. Near noon, the Sun is
high above the horizon—the Sun’s angle is greater,
and
so insolation is higher.
https://www.youtube.com/watch?v=Md4XC9jWVc
c

17. The Earth’s diverse environments by latitude
17

18. 18

19. Composition of the Atmosphere
Air and
sky
- is a
mixture of gases
dominated by
nitrogen and
oxygen.
19
Water vapor
-another
important constituent,
can condense into
clouds of liquid water
droplets

20. 20
!
Component gases of the lower atmosphere

21. Values show percentage by volume for dry
air.
Nitrogen and oxygen form 99 percent of our air, with
other gases, principally argon and carbon dioxide,
accounting for the final 1 percent.
21

22. OZONE IN THE
UPPER
ATMOSPHERE

23. Ozone Form of oxygen with a molecule consisting of
three atoms of oxygen O3.
23
Ozone hole,
September 24, 2006
https://www.youtube.com/watch?v=t27fdgK-x3g&feature=youtu.be

24. 24
What a Geographer Sees
https://ww
w.youtube.
com/watch
?v=4_rM6Q
DD9AE

25. Sensible Heat and
Latent Heat Transfer

26. Sensible Heat and
Latent Heat Transfer

27. Sensible Heat and Latent Heat Transfer
Sensible heat
-An indication of the intensity of kinetic energy
of molecular motion within a substance; it is
measured by a thermometer.
Latent heat
-Heat absorbed and stored in a gas or liquid
dur- ing the processes of evaporation, melting, or
sublimation.
27

28. The Global Energy
System

29. ALBEDO
The proportion of
shortwave radiant energy
scattered upward by a surface
is called its albedo and is
measured on a scale of 0 to 1.
For example, a surface that
reflects 40 percent of incoming
shortwave radiation has an
albedo of 0.40.
29

30. Counter radiation
Although the atmosphere is
colder than the surface, it also emits
longwave radiation, which is emit ted
in all directions, and so some
radiates upward to space while the
remainder radiates downward toward
the Longwave at most Earth's
surface. We call this downward flow
counter radiation.
30

31. GREENHOUSE EFFECT
Cloud layers, which are
composed of tiny water
droplets, are even more
important than carbon dioxide
and water vapor in producing a
blanketing effect because
liquid water is also a strong
absorber of longwave
radiation. This mechanism is
known as the greenhouse
effect 31

32. NET RADIATION
In places where radiant
energy flows in faster than it
flows out, net radiation is
positive, net radiation,
providing an energy surplus. In
other places, net radiation can
be negative. For the entire
Earth and atmosphere, the net
radiation is zero over year
32