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Heat, land and air
Chapter 13
Remember Specific Heat Capacity!

Near the surface:
Air warms easier than water, and soil heats easier than air.
Absorption of Heat


Most radiation absorbed
near top of soil.
Radiation absorbs
deeper in water and
spreads out over the
sample.

Warm water has
molecules that are
moving more quickly and
have more energy. The
more movement causes
more space in between
the molecules. Warm
water (or air) is less
dense than cooler water.
Cold sinks


Cooler water has less energy, little movement
and therefore is more dense.
So, cold sinks and warm rises but in which
direction?
Direction of wind (Day)


Warm air above ground,
rises up, while the
warming air above the
sea replaces it.
The wind blows in from
water to the land.
Wind direction (night)


Water keeps its warmth
much longer than the air,
so now the warm air is
above the water and
cooler air above the
land.
Blows from the land to
the sea.
Sea Breeze
Sea breezes help cool places near oceans
•Sea breezes form because water heats up much slower than land.
•Cool air over the ocean is heavier and more dense than the warm air
over land.
•The cool air nudges its way inland and can create a strong wind at
the surface.
•The bigger the temperature contrast between the air temperature
inland and the water temperature, the better chance of a sea breeze
developing and the stronger it will be.
Land breeze
•At night, heat loss through radiation means that the coastal air
becomes heavier, pushing the warmer sea air off the coast, giving
a land breeze.
•The strength of these breezes depends on the difference in
temperature over land and water, the instability of the warmer air,
the upper-air wind, friction, the shape of the shore and the size of
the body of water.
•These are very local phenomena that occur only when prevailing
winds are weak.
•Land breezes are generally much weaker than sea breezes,
since the temperature of the air varies more slowly during
nighttime, thereby ensuring some stability.