This document discusses weather and the factors that influence it. It defines weather as the condition of the atmosphere at a particular time and place, and identifies key weather variables like temperature, wind, moisture, precipitation and cloud cover. It then explains that insolation refers to the amount of sun energy reaching Earth, and that the angle of insolation depends on how high the sun is in the sky. The angle and intensity of insolation varies over locations and times of day, being greatest near the equator and at midday.

1. What is
weather?

2. Weather
• Weather it is the condition of the atmosphere
at a particular time and place .

3. What can cause the changes of
weather?
• Weather variables:
1) Temperature
2) Wind
3)Moisture
4)Precipitation
5)Cloud Cover

4. Insolation
• It is the amount of sun energy reaching the
Earth at a given time and place

5. What is the angle of insolation?
• a measure of how high the sun is in the sky
• measured from the horizon up to the position of
the sun

6. What happens as the angle increases or
decreases?
• As the angle of insolation increases, intensity
increases. (heat concentrated in smaller area.)

7. • As the angle of intensity decreases, heat is
spread out over a larger area.

8. Low angle: Less absorbed
High angle: More absorbed
• Intensity of insolation varies over the Earth because
of the curvature of the Earth.
Earth

9. Where is intensity the greatest and
lowest?
• Intensity greatest near
the Equator.
– Sun’s rays are direct
• Intensity low at the
poles

10. At what time is the angle and
intensity of insolation greatest?
•The noon sun has the greatest angle of insolation.

11. How to measure angle of insolation ?
• WE can measure ion angle of insolation

12. Why does the angle of insolation
change between midday and
evening?
The angle of insolation decreases because the
Earth’s rotation ,and the air temperature usually
decrease

13. Measuring Temperature