Consider the following statements regarding the incoming insolation on Earth

1. The equator receives less insolation than the tropics.

2. Insolation is more over the oceans than over the continents at the same latitude

3. The Ocean reflect more of the incoming insolation than Deserts.

Which of the statements given above is/are correct?

a) 1 only

b) 2  and 3 only

c) 1 and 3 only

d) 1, 2 and 3 only

Ans :a

Equator receives less insolation than tropic due to heavy cloud cover. Remember insolation is the amount of sunlight received at the surface of earth per unit area. So the clouds obstructs the sunlight and hence equator receives less insolation. Similarly, Oceans are significantly cloudier than continents and hence receive less insolation.

b)     For examination purpose, it’s very important to remember heat budget.

Insolation is the solar radiation that reaches the earth’s surface. It is measured by the amount of solar energy received per square centimetre per minute.

Insolation affects temperature. The more the insolation, the higher the temperature.

In any given day, the strongest insolation is received at noon.

Factors affect insolation (without the effect of the atmosphere):

• Angle of the sun
• Distance between the sun and the earth
• Duration of daylight

The longer the duration of daylight, the more the insolation received per day.

Also , reflecting the incoming insolation or incident light is called albedo . Deserts have higher albedo than the sea water. This is useful for the exam.