Download Heat in the Atmosphere

Heat in the Atmosphere
The sun’s energy is transferred to earth and the
atmosphere three ways
Radiation, Convection and Conduction
Temperature vs. Heat
 These are (2) different things
 Temperature – measurement of how rapidly or slowly
molecules move around

Heat – transfer of the energy that occurs as a result of a
difference in temperature between substances. (Ice Cube in
Bowl of Hot Water)
 TRANSFER OF HEAT ENERGY IS RESPONSIBLE
FOR EVERY WEATHER RELATED EVENT!!!!
Radiation
 The transfer of energy through space by
electromagnetic waves
 Does not heat the earth directly
Convection
Warmer less dense air rises, cooler
more dense air sinks
 The transfer of heat
by the flow of heated
material
 Pockets of air near
earth’s surface are
heated and rise
 The rising air begins
to cool and sinks
 Convection currents
are responsible for
most weather
Conduction
 The transfer of
energy that occurs
when molecules
collide or touch
 Substances must be
in contact with one
another
 Conduction only
affects the more
dense lower
atmosphere
The denser the material, the closer the
atoms, the better the conductor
Match the type of energy transfer
A
B
C
Convection
B
2. Radiation
A
3. Conduction
C
1.
 All the frequencies and wavelengths of radiation
 Includes radio, micro, infrared, visible light, UV, X-rays,
and gamma rays
Solar EM Radiation Penetration
 High energy
radiation
filtered out in
upper
atmosphere
 Much
infrared
also filtered
in
stratosphere
http://www.windows2universe.org/earth/Atmosphere/earth_atmosph_radiation_budget.html
Layers of the Atmosphere and Solar Radiation:
 Thermosphere, mesosphere, stratosphere filters all
wavelengths shorter than visible light
 Near the Earth's surface, the sunlight that does reach the
ground warms the Earth, which in turn warms the air
immediately above it.
 In the troposphere carbon dioxide, water vapor, and
methane absorb infrared rays and keeps energy in
troposphere
 Visible light is barely filtered in the atmosphere
Reflection:
The disruption and bending of solar rays, allows light
to come in at all angles and causes the sky to be blue
Scattering:
Solar energy that reaches the Earth and is reflected
back depending on characteristics such as color,
texture, composition, volume, mass, transparency,
state of matter, intensity of light, and amount of time
exposed
Albedo:
 The fraction of solar radiation that is reflected off the
surface
How Do We Affect the Atmosphere?
The greenhouse effect keeps the earth warm



The sun’s energy is trapped in the troposphere
Also called Global warming (rise in Earth’s surface
temperatures)
Polar ice can melt & sea level can rise naturally
The warming of the surface and lower
atmosphere of Earth that occurs when carbon
dioxide, water vapor and other gases in the
air absorb and reradiate the infrared
radiation (heat)
Greenhouse Gases
 carbon dioxide (CO2)




mainly from fossil fuels
methane (CH4) produced
by animals & other natural
sources
chlorofluorocarbons
(CFC's)
tropospheric ozone
(O3) comes mainly
from industry and traffic
nitrous oxide (N2O)
produced naturally in
soils and when the land is
fertilized.
Global Climate Change:
If the amount of solar energy that enters the atmosphere is
equal to the amount that escapes then the average
temperature will remain constant
A reduction of solar energy escaping back into space,
results in higher global temperatures (Global Climate
Change)
Changes in the amounts of GHG in the atmosphere have
been shown to be a factor in GCC
Human use of resources has led to increased CO2, CH4,
CFC, N2O and Water vapor in the atmosphere
Effect of the Angle of the Sun
a) The more direct the sunlight, the higher the
temperatures because the energy is concentrated in
a smaller area
b) As a result, seasons are determined by the tilt of the
Earth 23.5 o
c) Therefore, we are angled towards the sun during
summer and away during winter
d) We are closer to the sun during the winter and
farther away during the summer