The document discusses key concepts related to energy and heat transfer. It defines energy as the ability to do work, and describes different types of energy including potential, kinetic, thermal, and radiation. It explains how energy can be transferred through conduction, convection, and radiation. Key terms are introduced like blackbody, greenhouse effect, atmospheric windows, and albedo. Fundamental principles like the conservation of energy and heat transfer via conduction, convection and radiation are explained in the context of understanding Earth's climate and heat budget.

1. Geronimo R. Rosario

2.  Energy is the ability or capacity to do work on some
form of matter.

 Work is the measure of a quantity that is capable of
accomplishing macroscopic motion of a system due to
the action of a Force over a Distance.
◦ Force is the agent of change, and Work is a measure of the
change.

 Matter is anything that has mass and occupies space.

 Three most important ideas of the model:
◦ All substances are made of particles too small to see
◦ The particles are always in motion
◦ The particles have space between them

3.  Potential Energy- is the stored energy of position
possessed by an object.

◦ Gravitational Potential energy- is the energy stored in an object
as the result of its vertical position or height. The energy is stored
as the result of the gravitational attraction of the Earth for the
object.
◦ The gravitational potential energy (PEg) of any object is given as;

 PEg = mgh,

◦ Where m is the object’s mass, g is the acceleration of gravity, and
h is the object’s height above the ground.


4.  Elastic potential energy- is the energy stored in elastic
materials as the result of their stretching or compressing.
Elastic potential energy can be stored in rubber bands,
bungee chords, trampolines, springs, an arrow drawn into a
bow, etc.

 The elastic potential energy (PEe) of any object is given as;

 PEe = 0.5 kx2

 Where k is the constant of proportionality of the object and x
is the amount of compression of the object.

5.  Kinetic energy – is the form of energy that results
from object’s motion.

 The kinetic energy (KE) of an object is equal to half its
mass multiplied by its velocity squared; thus;

 KE = 1⁄2 mv2

 The atoms and molecules that comprise all matter
have kinetic energy due to their motion. This form of
kinetic energy is often referred to as heat energy.

6.  Things to note:

 Energy is not a
substance.
 It cannot be
weighed
 It does not take
up space
 Energy
describes a
condition
Law of Conservation of Energy: Energy cannot be created or destroyed. It
can only be transformed from one type to another or passed from one object to
another. (First law of thermodynamics)

7.  Temperature- is a measure of the average speed of the
atoms and molecules, where higher temperatures
correspond to faster average speeds.
 Thermal Energy - The total energy of all the particles in
a material.
 The total potential and kinetic energy in an object. It
depends on mass, temperature, and phase of an object.
 Thermal energy is synonymous to Internal energy
 The atmosphere and oceans contain internal energy.

8.  All of the particles that make up matter are
constantly in motion
 Solid= vibrating atoms
 Liquid= flowing atoms
 Gas= move freely
 Plasma= move incredibly fast and freely

 A plasma is a gas that has been energized to the
point that some of the electrons break free from,
but travel with, their nucleus. Ex. Lightning,
electric spark, neon lights

9.  Thermometer: Mechanical or electrical device for
measuring temperature. Early thermometer was
invented by Galileo.
 Scale: A series of equally measured sections that are
marked and numbered for use in measurement
Fahrenheit: Water freezes 32oF and
boils at 212oF
Celsius: Water freezes at 0oC and boils
at 100oC
Scientists use Kelvin to explain the
behaviour of gases.
“Absolute Zero” is measured in Kelvin –
which is the coldest possible
temperature 0 Kelvin = -273 ºC

10.  Formula for Conversion:

 oC = (5/9) x (oF-32)
 oF = (9/5) oC +32
 K = °C + 273

 Thermal expansion/contraction - change in volume of a material due
to temperature change.
 Occurs because particles of matter collide more or less as temperature
changes.

 Contract: Decrease in volume
 Expand: Increase in volume
 Temperature changes cause things to expand and contract
 Heated – usually causes expansion
 Cooled – usually causes contraction
 Usually more drastic in gases, then liquids then solids

11.  Heat- is energy in transfer other than as work or
by transfer of matter.
◦ When there is a suitable physical pathway, heat flows
from a hotter body to a colder one
 Heat Capacity: Amount of thermal energy that
warms or cools the object by one degree Celsius.
 Specific Heat: the amount of energy required to
raise the temperature of 1 gram of a substance by
1oC
 Calorie is the unit used for the amount of energy

13.  Latent- hidden
 Latent heat- the quantity of heat
gained or loss per unit mass as a
substance undergoes a change of
state at given temperature.
 Latent heat of melting- is the
energy needed to break the
intermolecular bonds that hold
water molecules rigidly in place in
ice crystals without an increase in
temperature.
 Latent heat of vaporization- Is
the amount of heat that must be
added to 1 gram of a substance at
its boiling point to break the
intermolecular bonds and
complete the change of state from
liquid to vapor (gas).
Latent heat of evaporation- the
heat energy that must be added to
one gram of a liquid substance to
convert it to a vapor at a given
temperature below its boiling point.
585 calories at 20oC at sea surface

14.  Latent heat is the energy absorbed by or released
from a substance during a phase change from a gas
to a liquid or a solid or vice versa.
 All pure substances in nature are able to change their state. Solids
can become liquids (ice to water) and liquids can become gases
(water to vapor) but changes such as these require the addition or
removal of heat. Heat that causes a change of state with no change
in temperature is called latent heat.
 Sensible heat is the energy required to change the
temperature of a substance with no phase change
 When an object is heated, its temperature rises as heat is added. The
increase in heat is called sensible heat. Similarly, when heat is removed
from an object and its temperature falls, the heat removed is also called
sensible heat. Heat that causes a change in temperature in an object is
called sensible heat

15.  Evaporation from lakes, oceans, rivers, etc. occurs for
temperatures lower than 100 oC
But it requires more
energy to do so

16.  Energy moves heat
in three ways
 Conduction
 Convection
 Radiation

17.  process of heat
transfer in
wave form,
without the use
or necessity of
a transmitting
medium. Ex:
insolation
(radiant
energy) from
the s
All things (whose temperature is above
absolute zero), no matter how big or
small, emit radiation.

18.  Most of the sun’s
energy is emitted from
its surface, where the
temperature is nearly
6000 K (10,500°F,
5815.6 oC). The earth,
on the other hand, has
an average surface
temperature of 288 K
(15°C, 59°F). The sun,
therefore, radiates a
great deal more energy
than does the earth.

19.  States that the amount of energy emitted by an object is
proportional to the object’s temperature.

◦ Stefan-Boltzmann Law describes this mathematically as;

 I =T4

 I is the intensity of the radiation in watts/m2,  is the Stefan-
Boltzmann constant (5.67 x 10-8 watts/m2/K4) and T is the
temperature of the body in K

◦ Hotter objects emit more energy than cooler ones
◦ Graybodies denote objects which emit some percentage of the
maximum amount of radiation possible at a given temperature
 Most solids and liquids
◦ True radiation emitted is a percentage relative to a blackbody and
reflects the emissivity of the object

20.  The earth emits most of its radiation at longer wavelengths between
about 5 and 25 μm, while the sun emits the majority of its radiation at
wavelengths less than 2 μm. For this reason, the earth’s radiation
(terrestrial radiation) is often called longwave radiation, whereas the
sun’s energy (solar radiation) is referred to as shortwave radiation

21.  The transfer of heat by the mass movement of a fluid
(such as water and air)
 The temperature gradients in the laminar boundary layer
induce energy transfer upward through convection
◦ This occurs any time the surface temperature exceeds
the air temperature
◦ Normally, this occurs during the middle of the day
◦ At night, the surface typically cools more rapidly than
air and energy is transferred downward

22.  Convection can be generated by two processes in fluids
◦ Free Convection
 Mixing related to buoyancy
 Warmer, less dense fluids rise
◦ Forced Convection
 Initiated by eddies and other disruptions to smooth, uniform flow
Free Convection
Forced Convection

23.  The transfer of heat from molecule to molecule within a
substance
 As the surface warms, a temperature gradient (rate of
change of temperature over distance) develops in the
upper few cm of the ground
 Temperatures are greater at the surface than below
◦ This transfers energy downward
◦ Surface warming also causes a temperature gradient
within a very thin sliver of adjacent air called the
laminar boundary layer
◦ Air is an extremely poor conductor of heat

25. ◦ Nearly two (2) calories on each square centimeter
each minute or 1367 W/m2
◦ Insolation annually varies by 7%
◦ Useful to think of a constant supply of radiation at the
top of the atmosphere
◦ Need to account for the relative amount of radiation
that is transmitted through the atmosphere, absorbed
by the atmosphere and surface, and scattered back to
space

26.  Scattering- is the process by which "small
particles suspended in a medium of a different
index of refraction diffuse a portion of the incident
radiation in all directions."
◦ With scattering, there is no energy transformation, but a
change in the spatial distribution of the energy
 Three different types of scattering
◦ Rayleigh scattering
◦ Mie scattering
◦ Non-selective scattering

27.  Rayleigh scattering mainly consists of
scattering from atmospheric gases.
◦ Involves gases, or other scattering agents that are
smaller than the energy wavelengths
◦ Scatter energy forward and backward
◦ Partial to shorter wavelength energy, such as those
which inhabit the shorter portion of the visible
spectrum
◦ A blue sky results

28.  Mie scattering is caused by pollen, dust, smoke, water
droplets, and other particles in the lower portion of the
atmosphere.
oLarger scattering agents, such as
suspended aerosols, scatter energy
only in a forward manner
oLarger particles interact with
wavelengths across the visible
spectrum
oProduces hazy or grayish skies
oResponsible for the white
appearance of the clouds
oEnhances longer wavelengths
during sunrises and sunsets,
indicative of a rather aerosol laden
atmosphere Longer radiation path lengths lead to
an increase in Mie Scattering and
reddish skies

29.  Non-selective scattering- It occurs in the lower
portion of the atmosphere when the particles are
much larger than the incident radiation. This
type of scattering is not wavelength dependent
and is the primary cause of haze.
◦ Water droplets, typically larger than energy
wavelengths, equally scatter wavelengths along the
visible portion of the spectrum
◦ Produces a white or gray appearance
◦ No wavelength is especially affected

30.  is the change in direction of
a wave front at
an interface between two
different media so that the
wave front returns into the
medium from which it
originated.
◦ Process does not increase
heat in the reflector as
energy is not absorbed
◦ In most instances, only a
portion of incident energy is
reflected
◦ Albedo = the percentage of
reflected energy
◦ Specular reflection is
reflection of energy as an
equally intense energy
beam

31.  Albedo- is the percent of radiation returning from a given surface
compared to the amount of radiation initially striking that surface.
Albedo, then, represents the reflectivity of the surface

32.  Solar radiation is the primary heat source for the atmosphere
 Most gases are transparent to solar radiation and, instead,
absorb terrestrial radiation
 Gases are also responsible for scattering incident energy
 Solar input must balance solar output
 Temperature increases/decreases if input is greater/less than
output
 Average Earth Temperature is 16o
C
 Without greenhouse gases, average T is -18oC
 Solar Energy is reradiated from the surface as a long wave.
 Surface of Earth (including oceans) is heated from above
 Atmosphere is heated from below
 The balance between incoming solar radiation, the absorption of
terrestrial radiation, and outgoing terrestrial radiation describes
the global energy budget

33.  Atmospheric Influences on Insolation
 Radiant energy incident upon the Earth-atmosphere system
is either absorbed, reflected, or transmitted by atmospheric
gases and/or the Earth’s surface
 Energy reflected and/or transmitted (scattered) does not
contribute to heating
 Absorbed energy encourages direct heating
 Absorption
 Particular gases, liquids, and solids in the atmosphere absorb
radiant energy
 Heat increases in the absorber while less energy is
transferred to the surface
 Although atmospheric gases are rather selective in the
wavelengths they absorb, they are overall poor absorbers of
energy

34.  Blackbody- any object that is a perfect absorber
(that is, absorbs all the radiation that strikes it) and
a perfect emitter (emits the maximum radiation
possible at its given temperature).
 Blackbodies do not have to be colored black;
they simply must absorb and emit all possible
radiation.
 Earth’s surface and Sun are blackbodies
 Selective absorbers- Objects that selectively
absorb and emit radiation, such as gases in our
atmosphere.

35.  States that good
absorbers are good
emitters at a
particular
wavelength, and
poor absorbers are
poor emitters at the
same wavelength.
 Atmospheric
Window- range of
wavelengths not
absorbed

36.  is the overall dynamic property of the earth's atmosphere,
taken as a whole at each place and occasion of interest,
that lets some infrared radiation from the cloud tops and
land-sea surface pass directly to space without
intermediate absorption and re-emission, and thus without
heating the atmosphere.
As the main part of the 'window'
spectrum, a clear electromagnetic
spectral transmission 'window' can
be seen between 8 and 14 µm. A
fragmented part of the 'window'
spectrum (one might say a
louvred part of the 'window') can
also be seen in the visible to mid-
wavelength infrared between 0.2
and 5.5 µm.

37.  There are 2 so-called atmospheric windows
 Solar window: lets in almost all visible light and shortwave infrared
light from the Sun
 Thermal window (confusingly also called the atmospheric window):
allows out some of the longwave infrared from the Earth
 These energy flows balance to maintain the Earth's temperature.

38.  Global heat budget is the balance between incoming
and outgoing solar radiation. Incoming solar energy
varies at different times of year and for different locations
across the globe.

39. An estimate of the heat budget for Earth. On an average day, about half of the
solar energy arriving at the upper atmosphere is absorbed at Earth’s surface.
Light (short-wave) energy absorbed at the surface is converted into heat. Heat
leaves Earth as infrared (long-wave) radiation. Since input equals output over
long periods of time, the heat budget is balanced.

40. Earth as a whole is in
thermal equilibrium, but
different latitudes are
not.
The average annual
incoming solar radiation (red
line) absorbed by Earth and
the average annual infrared
radiation (blue line) emitted
by Earth. Polar latitudes lose
more heat to space than they
gain, and tropical latitudes
gain more heat than they
lose. The amount of radiation
received equal the amount
lost at about 38°N and S.
The area of heat gained
(orange area) equals the
area of heat lost (blue areas)
so Earth’s total heat budget
is balanced.

41.  Energy imbalance – more energy comes in at
the equator than at the poles
 51% of the short-wave radiation (light) striking
land is converted to longer-wave radiation (heat)
and transferred into the atmosphere by
conduction, radiation and evaporation.
 Eventually, atmosphere, land and ocean radiate
heat back to space as long-wave radiation
(heat)
 Input and outflow of heat comprise the earth’s
heat budget

42.  Qs= Qr + Qe + Qh
 Where:
 Qs = solar radiation (100%)
 Qr = radiation (41%)
 Qe = evaporation (53%)
 Qh = conduction (6%)
 Example: If we have 2500 units of Qs, compute for the
Qr, Qe and Qh.
 Qs= 1025 + 1325 + 150

43. How solar energy input varies
with latitude.
Equal amounts of sunlight are
spread over a greater surface
area near the poles than in the
tropics.
Ice near the poles reflects much
of the energy that reaches the
surface there.
The atmosphere reflects, scatters and absorbs solar radiation. At high
latitudes solar radiation travels a longer path through atmosphere.

44. Uneven Solar Energy Inputs: Earth is heated
unevenly by the sun due to different angles of
incidence between the horizon and Sun.
This angle of incidence is
affected two factors:
1) Latitude: solar inputs are
most dense when the
sun is overhead in the
tropics; reflection is low.
The reverse holds true in
polar regions.
2) Season: Due to Earth’s
annual orbit around the
Sun on an axis tilted by
23.5º.

45.  Latitude (o) Heat received (g cal/cm2/min)

 0 0.339
 10 0.334
 20 0.320
 30 0.297
 40 0.267
 50 0.232
 60 0.193
 70 0.160
 80 0.144
 90 0.140

46.  Heat budget for particular latitudes is NOT
balanced
 Sunlight reaching polar latitudes is spread over a
greater area (less radiation per unit area)
 At poles, light goes through more atmosphere so
approaches surface at a low angle favoring
reflection
 Tropical latitudes get greater radiation per unit
area and light passes through less atmosphere
so they get more solar energy than polar areas

47.  Atmosphere and ocean one interconnected
system
 Change in atmosphere affects ocean
 Change in ocean affects atmosphere

48.  Equatorial areas excess heat
 Polar regions heat deficient

50. Warm equatorial water flows to higher latitudes
Cool Polar water flow to lower latitudes
Re-distribution of heat
• Heat gained at Equatorial latitudes
• Heat lost at higher latitudes
• Winds and ocean currents redistribute heat around the
Earth
Oceans do not boil away near the equator or freeze solid near the
poles because heat is transferred by winds and ocean currents
from equatorial to polar regions.

51. • To compensate for this energy
imbalance, winds in the
atmosphere and currents in the
oceans transport cold air and
water toward the equator
• About 1/3 of this transport
occurs from the evaporation of
tropical waters and subsequent
transport into high latitudes,
where it condenses and
releases latent heat
• About 1/3 occurs from the
poleward transport of warm
waters by ocean currents
• The remaining 1/3 occurs from
middle latitude cyclones and
anticyclones

52. ►Due to Energy transfer we get form solar energy
and other forms we get different weathers.
►The Effects of the energy transfers in the future
could result in melting Ice caps, higher sea
levels , flooding, and warmer climate .
► The Polar Ice Caps absorb a lot of the CO2
and solar radiation.
►If these melt then there will be nothing to reflect
the harmful radiation and to absorb CO2 .

53. ◦ Earth revolves about the Sun along an ecliptic plane
◦ Distance varies
 Perihelion (Jan 3; 148 mil km, 91 mil mi)
 Aphelion (July 4; 152 mil km, 94 mil mi)
◦ Total variation is about 3%
◦ Using the inverse square law, radiation intensity varies
by about 7% between perihelion and aphelion

54.  Aphelion- the point in the orbit of an object in
the solar system that is farthest away from the
sun.
◦ 152,200,000 km distance
◦ July 4
◦ 1.88 cal
 Perihelion- point nearest the sun in the orbit of
a planet
◦ 148,500,000 km distance
◦ January 3
◦ 2.01 cal

55. ◦ Earth rotates on its axis once
every 24 hours
◦ Axis of rotation is offset 23.5o
from a perpendicular plane
through the ecliptic plane
◦ Because the axis of rotation is
never changing, the northern
axis aligns with the star Polaris
◦ Hemispheric orientation
changes as the Earth orbits the
Sun
◦ A particular hemisphere will
either align toward or away from
the Sun, or occupy a position
between the extremes

56.  Equinox- either of the two
annual crossings of the
equator by the Sun, once
in each direction, when the
length of day and night are
approximately equal
everywhere on Earth.
 The equinoxes occur
around March 21 and
September 23

 Vernal equinox- March 21
(the sun shines directly
above the equator)
 Autumnal equinox –
September 21 (the sun
shines directly above the
equator)

57.  Solstice- either of the
times when the Sun is
farthest from the equator,
on or about June 21 or
December 21

 Summer solstice- June
21 (the sun shines down
directly over the tropic of
Cancer 23o 27’N )
 Winter solstice-
December 21 (the sun
shines down directly over
the tropic of Capricorn
23o 27’S )

58.  Seasons do NOT arise from the distance the Earth is from the
Sun but rather as a result of the Earth’s annual motion and axial
inclination – the tip of our planet with respect to its orbital plane.
As we move around the Sun, the orientation of our planet gives
us seasons.