seasons and insolation

1. Insolation

2. Insolation

3. Insolation –
-incoming solar radiation
-sunlight

4. Insolation –
-incoming solar radiation
-sunlight
-the sun is the earth’s primary source of energy
-the sun releases electromagnetic energy
(there are 7 types)

6. Insolation –
-incoming solar radiation
-sunlight
-the sun is the earth’s primary source of energy
-the sun releases electromagnetic energy
(there are 7 types)
Intensity of Insolation-
-how strong the sun is

7. Angle of Insolation –
-the height of the sun
-the greater the angle, the stronger the sun
(highest angle is 90o)

8. Angle of Insolation –
-the height of the sun
-the greater the angle, the stronger the sun
(highest angle is 90o)
-the sun is highest at noon
-the noon sun is higher in summer than winter.

9. Duration of Insolation –
-hours of daylight in a day
-for NY, longest day is June 21 and
the shortest day is December 21
-varies with latitude and season

10. Insolation –
-varies with latitude because the earth’s axis is
tilted at 23 ½ °
Which color absorbs sunlight best? This is
important because the surface of the earth
varies in color and texture.
black with rough surface
Best reflector:
-white with a smooth surface

12. Which season is it?

13. Which season is it?

14. Which season is it?

17. 1 2

18. Earth Seasons -caused by:
1) tilt of earth’s axis
2) revolution of earth around the sun
Seasons: (northern hemisphere, NY)
-spring equinox (Mar 21)  12 hours daylight
-summer solstice (Jun 21)  15 hours daylight
-fall equinox (Sep 23)  12 hours daylight
-winter solstice (Dec 21)  9 hours daylight

29. As insolation increases, temperature __________

30. As insolation increases, temperature _increases_
The earth gives off heat, called
terrestrial radiation
If the earth takes in more insolation than heat
radiated, the temperature rises
If the earth takes in the same amount of
insolation as heat radiated, it is in
radiative balance. This occurs daily at approx.
3:00 pm. It occurs annually during the last
week in July and the last week in February.

31. Temperature lag-
-the average warmest day of the summer
occurs in late July, around a month after the
longest day of the year.

34. The next slide is beyond the scope of this topic.

35. The Greenhouse Effect-
- visible light from the sun (short wavelength)
is absorbed and re-radiated by the earth as
infrared energy (heat-long wavelength)
-caused mostly by the presence of carbon
dioxide (CO2), water, and methane in the
earth’s atmosphere
The Ozone Layer-
-protective layer in the stratosphere (about 15
miles up) that traps harmful ultraviolet (UV)
rays from the sun. The ozone layer is not
directly related to the greenhouse effect, or to
climate change.