1. There are three main methods of heat transfer: conduction, convection, and radiation. 2. The Earth is heated through radiation from the sun, with some energy being absorbed, some reflected, and some transmitted through substances like water and air. 3. Factors like land/water distribution, altitude, latitude, and cloud cover contribute to geographic and climatic differences in surface temperatures around the world.

1. Heating of the Earth
• Energy Transfers
– Co nd uc tio n: transfer of
heat from one object to
another through touch.
• A spatula warms up after
sitting in a hot pan.
• Metals are the best
conductors of heat,
whereas air is the worst
conductor of heat.

2. Heating of the Earth
• Energy Transfers
– Co nve c tio n: transfer of
heat from one place to
another through
circulation.
• In the ocean, warm
currents move heat
from the equator to
higher latitudes.

3. Heating of the Earth
• Energy Transfers
– Ra d ia tio n: radiant
energy that is emitted by
an object.

4. Heating of the Earth
• The atmosphere is heated
by radiation.
• There are 4 laws regarding
radiation.
1. All objects, at any
temperature, emit
radiant energy.
2. Hotter objects radiate
more total energy per
unit area than colder
objects do.

5. Heating of the Earth
• The atmosphere is heated by
radiation.
• There are 4 laws regarding
radiation.
3. The hottest radiating
bodies produce the
shortest wavelengths
with maximum radiation.
4. Objects that are good
absorbers of radiation
are also good emitters.

6. Heating of the Earth
• Solar Radiation
– There are 3 different results when radiation
strikes an object.
1. Some energy is absorbed by the
object.
2. Substances such as water and air
are transparent to certain
wavelengths of radiation.
3. Some radiation may bounce off the
object without being absorbed or
transmitted.

7. Heating of the Earth
• Solar Radiation
– Reflecting: light bounces off an object
in 1 direction.
– Scattering: light bounces off an object
in several directions; the total amount
of energy is divided up into the various
rays.
– Absorption: an object takes in the heat
and energy received by radiation.

8. Solar Radiation

9. Temperature Differences
• Land and Water
Differences
– Land heats and cools more
quickly than water.
– The temperature range is
greater for land than water.
• The land heats up to a higher
temperature than water can
and will cool lower than water
can.
• In the Northern Hemisphere,
there is 39% land; whereas
the Southern Hemisphere has
19% land.
– What does this indicate?

10. Temperature Differences
• Geographic
Differences
– In California, the wind
blows mainly from the
water to the land and
the temperatures stay
relatively consistent.
– In New York, the wind
blows mainly from the
land and the
temperatures change
frequently.

11. Temperature Differences (cont’d)
• Seattle, WA and Spokane, WA
are a couple hundred miles
away from each other, but
because there is a mountain
range between them, they have
different climates.
– Seattle is on the western side of
the mountains and receives winds
from the ocean resulting in little
temperature changes.
– Spokane is on the eastern side of
the mountains where there is no
wind from the ocean has bigger
temperature changes.

12. Temperature Differences
• Altitude Differences
– Two cities in Ecuador, Quito
and Guayaquil, are close to
each other, but have
different average
temperatures.
• Quito is high in the mountains
and has a lower average
temperature.
• Guavaquil is close to the sea
level and has a higher
average temperature.

13. Temperature Differences
• Cloud Cover and Albedo
– A d o is the amount of
lbe
radiation that is reflected
back to space.
• Clouds have a high albedo,
leading to less solar
radiation reaching Earth,
causing lower
temperatures during the
day.
• At night, clouds trap heat in
the atmosphere and keep
the temperature higher.

14. World Distribution of Temperature
• I o the rm s are lines that show
s
differences in temperature
(similar to contour lines on a
topographic map) on an
isothermal map.
– The temperatures on these maps
are taken at the same elevation in
order to eliminate any differences
in altitude.
– The higher latitudes have cooler
average temperatures and have
greater temperature changes.
– Latitudes close to the Equator
have higher average temperatures
and very little temperature
changes.