1. Heat and Air Temperature
Earth Science
Mr. Bimber

2. What factors affect air Temperature?
Insolation (incoming solar radiation)
Clouds
Water
Elevation
Ground surface

3. Insolation: latitude
Higher latitudes get the sun’s rays at a low angle, so they’re spread out over a greater area.
Near the equator, the sun’s energy is greater.

4. Insolation: time of day
Morning and evening sun are at a lower angle.

5. Insolation: time of year
Earth’s axis tilt:
the sun’s rays hit
at a lower angle
in winter
than in summer.

6. Cloud cover: daytime
Clouds reflect more
of the sun’s rays.

7. Cloud cover: night Heat rays from earth are reflected back more
on cloudy nights.
Clear nights get colder.

8. Water Water has a high specific heat. It takes more energy,
and longer to heat up
or cool down than land.

9. Water nearby Temperature changes much less downwind of
oceans and large lakes.

10. No water nearby… Temperature changes a lot in dry regions far
away from oceans or
large lakes.

11. Water releases heat when…
heat energy is
released when
water condenses
from gas to liquid,
or freezes.

12. Water releases heat when…
Air in clouds warms
when they rain or snow,
so they rise higher
because of convection.
That’s why these
thunderclouds are tall.

13. Water releases heat when…
Night air is warmed
when water condenses
as dew or frost.
It doesn’t usually get
much colder than the
“dew-point temperature”.

14. Water absorbs heat when…
Air gets cooled when its
heat energy is needed
to melt ice or evaporate
liquid water.
(Sweden’s “Ice Hotel” is
built every December;
still melting in May.)

15. Elevation
The higher you go,
the colder it gets.

16. Ground cover Dark surfaces, like asphalt roads and rooftops
absorb more heat
than light colored
surfaces.

17. Why is this rooftop green?
It saves energy and
money.
Plants help cool the air
through evaporation.

18. Humidity Humidity is the amount of water vapor in the air.
Warm air can hold more water vapor than cold air.

19. Relative humidity
Relative humidity is the percent humidity compared to the humidity limit at the current temperature.

20. Humid air feels warmer.
Your body cools itself by evaporating perspiration.
When it’s humid, less water evaporates from your skin, so you can’t cool down as well as you can in dry air.

21. Humidity can affect temperature.
When relative humidity goes over 100%,
fog, dew, or frost forms.
These release heat energy to the air, warming it.

22. What is “wind chill”?
Wind carries your body heat away, and helps water evaporate from your skin, cooling it.
The “wind chill” is what the temperature feels like because of the wind.

23. Temperature factors Factors affecting it:
Insolation
Clouds
Water
Elevation
Ground cover
Factors affecting how cold we feel:
Humidity
wind