Download Wind and Energy Notes File

Energy and Winds
Nature of Energy
Living organisms need energy
for growth and movement.
Energy
 The ability to do work!
 The combination of energy and matter make up the
universe
What is the source of our energy?
The source of
practically all
our energy is
the Sun.
Heat Transfer
 Heat transfers in three ways:
 Conduction
 Convection
 Radiation
Conduction
The transfer of heat from one particle of matter to another
by direct particle to particle contact.
Convection
 The transfer of heat through movement of matter.
 Occurs in liquids and gases
Radiation
 Transfer of energy through electromagnetic waves
 Matter is not required
 Radiation from the sun!
Why is Chicago
Known as the
Windy City?
► Wind is the movement of air from an area of high pressure to an
area of low pressure.
► It is the movement of air caused by uneven heating of the
Earth's surface.
►Global air circulation follows a general
pattern of convection . Air flows from the
equator to the poles and back again.
►The area near the equator receives the
most concentrated solar radiation,
causing the air above it to heat up rapidly.
As it heats up, it expands, becoming less
dense and more buoyant.
►This change in density causes it to rise. Air
at the very top of the rising mass cools.
► The cooler the air gets, the more dense it gets causing it to sink back to earth.
This cooler air is forced to flow toward the equator, where the process begins
again.
► The key factor driving convection is density – warm air is less dense and more
buoyant than cold air.
Density
Air Pressure
► Local air circulation
► During the day, land absorbs heat from the
sun better than water, so it warms up faster
and warms the air above it
► Water holds heat better than land, so it warms
the air at night.
In a high pressure area,
air will (rise, sink)
because the air is
(less, more) dense.
This is because the air is
(cold, warm)
and (rises, sinks).
In a low pressure area,
air will (rise, sink)
because the air is
(less, more) dense.
This is because the air is
(cold, warm)
and (rises, sinks).