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
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