Transcript Energy From the Sun (Teks 8.10A)

Energy From the Sun
(Teks 8.10A)
• Nuclear Energy is energy in the nucleus (core) of an atom.
Atoms are tiny particles that make up EVERY object in the
universe. There is enormous energy in the bonds that hold
atoms together.
• The Sun is made of Hydrogen Atoms. During a process called
Fusion, 4 Hydrogen atoms combine to form one Helium atom,
with a loss of matter. This matter is emitted as Radiant Energy.
Nuclear Energy in Sun
Remember the Equator Equals Hot
• Our activity with the flashlight and graphing
paper demonstrated to us that the equator
gets the most direct rays from the Sun.
How is Heat from the Sun transferred
through the Atmosphere
The sun's energy moves through space, then through the earth's atmosphere and finally
reaches the earth's surface. The sun's radiation warms the earth's atmosphere and surface
and becomes heat (thermal) energy. This heat energy is transferred through the atmosphere
by one of three mechanisms:
1. Radiation
2. Conduction
3. Convection
Radiation (Radiant Energy)
• Energy from the Sun is
absorbed by matter
(even us) on Earth by
Radiant Energy
(Radiation)
• Radiation is the transfer
of heat by
electromagnetic waves.
Conduction
• Conduction is the
transfer of heat from
one molecule to
another in a substance.
• Some matter (most
metals) are good
conductors. Others are
not very good
insulators.
Convection
• Convection is the transfer
of heat through a fluid,
like water and air.
• Earth’s surface absorbs
heat and warms the air
above it. Warm air
expands, becomes less
dense, and rises. Cooler
air rushes in to replace it.
This exchange causes a
circulation of air (thermal
cell).
Convection
• Convection transfers heat vertically into the
atmosphere. In order for heat to be
transferred into other regions of the Earth, it
must be moved by wind!
Where Water Meets Land –
There Will Be Wind
Land Heats Faster than Water.
In the day, warm air over
land rises, and cool air over
water rushes in to fill the
spot. This creates a SEA
BREEZE.
Because the land also cools
faster than water, at night
the air above the water is
warmer, rises, and the
cooler air from land rushes
in creating a LAND BREEZE.
High and Low Pressure Systems
High pressure systems (A.) are generally associated with fair
weather.
Low pressure systems (B.)are often associated with adverse
weather conditions.
Experiencing High and Low Pressure
• You will be given a piece of wood and a screw.
• You will use high pressure to screw into the
wood.
• As you do this think of the clockwise motion
and the pressure you are using.
• Then you will unscrew by using low pressure
and your motion will be counter-clockwise.
When air spirals into the low, it is converging
into the low. When air converges near the
surface, it is forced to rise. As air rises, it may
condense and form clouds and precipitation.
This is why low pressure systems are often
associated with adverse weather conditions.
Conversely, high pressure systems are
generally associated with fair weather. When
air spirals out of the high, it is actually
diverging. As air diverges from the high, the air
above the surface must sink in order to replace
the air that is moving away from the high.
Sinking air warms and tends to evaporate any
clouds that may be present.