Transcript Heat Transfer and Winds

Heat Transfer and Winds
Heat is transferred in three ways
Radiation
Conduction
Convection
Convection Currents
 Warm
air rises, then cools and
become more dense
 Cool air sinks back toward the
ground
 Heat is transferred mostly by
convection within the
troposphere
 Winds
are caused by differences in
air pressure.
 As air becomes less dense when it
is heated, its air pressure
decreases.
 Cool, dense air with a higher
pressure forces the warm air to rise.
Wind Direction
Wind direction is determined with a wind
vane
 The direction of the wind vane tells you
where the wind is coming from

Wind speed can be measured
by an anemometer.


When wind blows over your skin, it
removes body heat and makes you feel
colder. The increased cooling a wind can
cause is called the wind-chill factor.
Local Winds
Are caused by the unequal heating of
Earth’s surface within a small area.
 A sea breeze happens during the day
when cool air moves from the sea to the
land.
 A land breeze takes place at night when
cooler air moves from the land to the
sea.

Global Winds
Are created by the unequal heating of
Earth’s surface over a large area
 Major global wind belts are the trade
winds, the polar easterlies, and the
prevailing westerlies.

Coriolis effect

Is the effect of Earth’s rotation on the
direction of winds and currents.
Jet Streams
Bands of high-speed winds about 10 km
above Earth’s surface.
 Generally blow from west to east at
speeds of 200 to 400 km/hr
 They follow a wavy path
