What is weather?

Weather• Weather it is the condition of the atmosphere

at a particular time and place .

What can cause the changes of weather?

• Weather variables:

1) Temperature

2) Wind

3)Moisture

4)Precipitation

Insolation • It is the amount of sun energy reaching the

Earth at a given time and place

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

What happens as the angle increases or decreases?

• As the angle of insolation increases, intensity increases. (heat concentrated in smaller area.)

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

Low angle: Less absorbedHigh angle: More absorbed

• Intensity of insolation varies over the Earth because of the curvature of the Earth.

Earth

Where is intensity the greatest and lowest?

• Intensity greatest near the Equator.

– Sun’s rays are direct

• Intensity low at the poles

At what time is the angle and intensity of insolation greatest?

•The noon sun has the greatest angle of insolation.

How to measure angle of insolation ?

• WE can measure ion angle of insolation

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

Measuring Temperature